RubmdHealth TipThe Complete Health Guide Featuring Vitamins and Minerals from A to Z

The Complete Health Guide Featuring Vitamins and Minerals from A to Z

Our bodies require a number of essential nutrients in order to function properly. Vitamins and minerals play a vital role in all bodily processes including bone and tissue growth and repair, hormone and enzyme production, metabolism and more. Getting adequate amounts of these micronutrients can prevent deficiency and reduce the risk of many chronic diseases.

Vitamin A

Overview and Functions

Vitamin A is a fat-soluble vitamin that supports many critical bodily functions. It exists naturally in two forms:

  • Retinols: animal sources like dairy and eggs
  • Carotenoids: plant sources like fruits and vegetables

Once ingested, these compounds are converted into active forms of vitamin A like retinal and retinoic acid. Vitamin A helps with:

  • Vision – retinal combines with opsin proteins to form rhodopsin, allowing the eye to detect light
  • Gene expression and cell differentiation
  • Immune function
  • Reproduction
  • Embryonic development
  • Antioxidant effects

Deficiency and Toxicity

Vitamin A deficiency can lead to severe visual impairment and blindness. It may also increase susceptibility to infections. Populations at risk include those with poor nutrition status and certain genetic defects. Taking vitamin A supplements can correct and prevent deficiencies.

Consuming extremely high amounts of preformed vitamin A from supplements, liver and fish liver oils can cause toxicity symptoms like liver damage, bone loss, hair loss and abdominal pain. Carotenoid forms from plants are not known to cause toxicity.

Dietary Sources

The RDI for adults is 900 mcg RAE (retinol activity equivalents) per day. Food sources include:

  • Liver
  • Fish eggs and oils
  • Dairy products
  • Fortified cereals
  • Red, orange, dark green vegetables
  • Fruits like mango, papaya cantaloupe

Vitamin B1 (Thiamine)

Overview and Functions

Vitamin B1, also called thiamine, is one of eight B complex vitamins required for health. We must obtain it from food sources because the body cannot produce it. Thiamine acts as a coenzyme used to metabolize nutrients for energy production. It also supports nerve, heart, muscle and brain function.

Deficiency and Toxicity

Thiamine deficiency can lead to a condition called beriberi, characterized by nerve and heart damage. Other deficiency symptoms may include weight loss, confusion, irritability and impaired mental function. Chronic alcoholism can deplete thiamine stores in the body and lead to deficiency. Consumption from foods does not cause toxicity, although adverse effects have occurred in people taking high dose supplements.

Dietary Sources

The RDI for thiamine is 1.2mg per day for men over age 14 and 1.1mg per day for women over 18. The best food sources include:

  • Whole grains and enriched/fortified breads and cereals
  • Pork and ham
  • Trout and salmon
  • Potatoes
  • Legumes like lentils, black beans and soybeans
  • Nuts and seeds
  • Green peas

Vitamin B2 (Riboflavin)

Overview and Functions

Vitamin B2, also called riboflavin, acts as an antioxidant and vital coenzyme in cellular metabolism. It helps convert nutrients from food into useful bodily fuel. Riboflavin also assists with:

  • Breakdown of fats, carbs and proteins
  • Red blood cell production and function
  • Cellular growth and respiration
  • Conversion of vitamin B6 and folate into active forms

By aiding other B vitamin processes, riboflavin helps maintain healthy vision, skin, hair, liver and nervous system function.

Deficiency and Toxicity

Low riboflavin intake or absorption can lead to cracking and reddening of the lips and inflammation of the mouth and throat. Deficiency may also cause normocytic anemia. Toxicity from high vitamin B2 intake is unlikely because excess amounts are excreted in urine.

Dietary Sources

The RDI values for riboflavin are 1.3 mg/day for adult men and 1.1 mg/day for women. Some food sources rich in riboflavin include:

  • Milk and dairy products
  • Eggs
  • Salmon and organ meats
  • Mushrooms
  • Broccoli
  • Asparagus
  • Spinach
  • Avocados
  • Soybeans
  • Fortified cereals
  • Wheat germ

Vitamin B3 (Niacin)

Overview and Functions

Vitamin B3 consists of the organic compounds nicotinic acid and nicotinamide, collectively called niacin. This water-soluble micronutrient serves vital roles in cellular metabolism and DNA production and repair by carrying hydrogen and electrons. Niacin helps convert food into energy and produces metabolism-regulating molecules like steroid hormones.

Other key jobs include aiding circulation and cognitive function, balancing blood cholesterol and supporting digestive and skin health. The active forms of vitamin B3 also assist the central nervous system and promote healthy vision.

Deficiency and Toxicity

Deficiency can lead to pellagra, which causes diarrhea, dementia and skin rash. It is rare except in areas dominated by corn-based food, which contains bound niacin that doesn’t get absorbed well. Mild deficiencies are more common and can contribute to headaches, exhaustion, indigestion and poor circulation.

Consuming large, sustained doses of niacin supplements can lead to toxic symptoms like liver damage, stomach ulcers, vision loss, high blood sugar, dizziness and skin flushing. RDI levels from normal diets are not toxic.

Dietary Sources

The RDI for niacin is 16 mg NE (niacin equivalents) for adult men and 14 mg NE for women. Some rich food sources are:

  • Meat and poultry
  • Fish like tuna and salmon
  • Seeds and whole grains
  • Nuts like peanuts
  • Potatoes
  • Avocados and leafy greens
  • Mushrooms
  • Dairy

Fortified cereals, nutritional yeasts and some energy drinks also provide niacin.

Vitamin B5 (Pantothenic Acid)

Overview and Functions

Vitamin B5, also called pantothenic acid, is a water-soluble micronutrient widespread in plant and animal foods. Your body requires B5 to synthesize essential compounds like coenzyme A (CoA), which participates in over 100 metabolic processes including:

  • Making blood cells and hormones
  • Converting nutrients to energy
  • Breaking down fats and carbs
  • Forming neurotransmitter acetylcholine

B5 also enables bodily production of vitamin D and red blood cells and helps maintain healthy skin and hair.

Deficiency and Toxicity

Deficiency is very rare but may cause numbness, muscle cramps, exhaustion and hypoglycemia. Toxicity is almost unheard of due to efficient bodily excretion of excess amounts. Signs might include diarrhea and water-electrolyte imbalances.

Dietary Sources

Recommended intakes are 5 mg/day for adults under 70. Vitamin B5-rich foods include:

  • Organ meats like liver and kidneys
  • Fish and shellfish
  • Poultry
  • Broccoli
  • Avocados
  • Sweet potatoes
  • Mushrooms
  • Lentils and legumes
  • Nuts and seeds
  • Eggs and dairy

Smaller amounts occur in whole grain products, oats, fruits and vegetables.

Vitamin B6

Overview and Functions

Vitamin B6 is a water-soluble compound that exists in three forms: pyridoxal, pyridoxamine and pyridoxine. This essential nutrient acts as a vital coenzyme for protein, carbohydrate and lipid metabolism. B6 helps the body:

  • Break down and derive energy from amino acids, glycogen and lipids
  • Form neurotransmitters for normal nerve and brain activity
  • Make hormones like serotonin and dopamine
  • Form hemoglobin to transport oxygen in blood

B6 also benefits immune function and histamine response. It further aids vitamin B12 absorption and prevents homocysteine buildup linked to heart disease.

Deficiency and Toxicity

Deficiency can cause anemia, convulsions, depression, confusion, mouth inflammation and impaired immune function. People prone to low B6 levels include the malnourished elderly, alcoholics, those on certain medications and people with autoimmune disorders, kidney disease and metabolic disorders.

Consuming extremely high vitamin B6 supplements long-term can possibly lead to nerve damage and skin lesions. Amounts from regular diets do not cause toxicity.

Dietary Sources

The RDI for adults up to age 50 is 1.3 mg daily and 1.7 mg over 50. Some foods rich in B6 vitamins are:

  • Poultry like turkey and chicken
  • Fish like tuna and salmon
  • Organ meats
  • Potatoes with skin
  • Starchy vegetables
  • Non-citrus fruits
  • Legumes and soy foods
  • Eggs
  • Seeds like sunflower
  • Fortified cereals
  • Avocados

Vitamin B7 (Biotin)

Overview and Functions

Biotin, formerly called vitamin B7 or vitamin H, belongs to the B complex family. This water-soluble micronutrient acts as a vital cofactor for enzymes involved in metabolizing fats, carbohydrates and amino acids for cellular energy. Without it, macronutrients cannot get properly converted into useable bodily fuel.

Biotin further enables key functions like:

  • Cell growth and renewal
  • Nutrient metabolism
  • Cognitive processes and central nervous system signaling
  • Regulating gene expression
  • Balancing blood sugar and lipids

Adequate biotin status also supports healthy hair, skin, eyes, liver function and fetal development during pregnancy.

Deficiency and Toxicity

Deficiency is quite rare but can cause hair loss, conjunctivitis, dermatitis, depression, lethargy and neurological symptoms in severe cases. Pregnant women, heavy drinkers, smokers and the malnourished are most susceptible. Biotin supplements or an improved diet can reverse deficiencies.

Toxic effects only occur from exceptionally high intake of supplements over long periods. Symptoms may include skin rashes and digestive issues. Amounts found naturally in foods are not toxic due to efficient bodily excretion.

Dietary Sources

The RDI for biotin is 30 mcg per day in adults. Some biotin-rich dietary sources include:

  • Organ meats like liver and kidneys
  • Egg yolks
  • Salmon and other fatty fish
  • Meat and poultry
  • Seeds and nuts
  • Sweet potatoes
  • Mushrooms
  • Bananas and raspberries
  • Avocados
  • Cauliflower

Vitamin B9 (Folate/Folic Acid)

Overview and Functions

Folate refers to the many natural forms of vitamin B9 found in foods, while folic acid denotes the synthetic type used in supplements and fortified foods. This water-soluble nutrient plays crucial roles in cell division and growth by assisting DNA and RNA synthesis.

Folate also helps form red blood cells and enables many bodily processes including:

  • Amino acid metabolism
  • Circulatory health
  • Brain and nervous system functioning
  • Mental faculties like mood and cognition
  • Fetal and child development and preventing certain birth defects
  • Preventing changes to DNA that cause cancer

Deficiency and Toxicity

Low folate status affects all cell types with rapid turnover like intestinal and mouth tissues, skin, hair and bone marrow. Symptoms include anemia, mobility issues and neurological problems. Alcoholism, liver disease, diarrhea and poor diet raise deficiency risks. Taking folic acid supplements reverses problems.

Getting extremely high supplemental doses can mask vitamin B12 deficiency symptoms, potentially causing nerve degeneration. Too much folic acid may be tied to higher cancer risk in certain people as well. But folate from regular diets is not considered toxic.

Dietary Sources

The RDI for folate is 400 mcg DFE daily. Folate occurs abundantly in foods like:

  • Legumes
  • Seeds
  • Dark leafy greens
  • Asparagus
  • Broccoli
  • Citrus fruits
  • Liver and kidneys
  • Nutritional yeast
  • Fortified products like cereals

Vitamin B12

Overview and Functions

Vitamin B12 refers to a group of compounds called cobalamins which act as vital coenzymes and methyl donors in the body. These cofactors help synthesize DNA, form red blood cells, maintain healthy nerve cells and enable cell division and growth.

B12 also benefits cardiovascular health, energy levels, mood, memory, digestion, vision and fetal development during pregnancy. Other roles include aiding production of the mood-regulating brain chemicals serotonin and dopamine.

Deficiency and Toxicity

Deficiency often stems from the inability to separate B12 from food proteins, such as in pernicious anemia or from low stomach acid. Symptoms include fatigue, neurological issues and megaloblastic anemia. Vegans must supplement their diets with B12. Correcting deficiencies requires B12 pills or shots.

Getting excessively high amounts from supplements or shots may potentially cause breakouts, diarrhea, blood pressure changes and insomnia in those with absorption disorders. But food-based B12 does not pose toxicity concerns for healthy people.

Dietary Sources

The RDI is 2.4 mcg for ages 14+, rising to 2.6 to 2.8 mcg for women during pregnancy and breastfeeding. Some dietary sources include:

  • Organ meats like liver
  • Meat and fish
  • Shellfish like clams and oysters
  • Eggs and dairy products
  • Nutritional yeast
  • Fortified milk alternatives and cereals

Vitamin C

Overview and Functions

Also called L-ascorbic acid, vitamin C is a water-soluble nutrient that acts as a vital antioxidant in the body. It neutralizes unstable molecules called free radicals which can harm cellular structures. Vitamin C also enables important jobs like:

  • Forming collagen connective tissues
  • Aiding wound healing
  • Strengthening blood vessels
  • Improving iron absorption
  • Supporting cellular functions
  • Boosting immunity by stimulating white blood cell production
  • Safeguarding eye and brain health

Fruits and vegetables rich in vitamin C help combat oxidative stress underlying many chronic diseases.

Deficiency and Toxicity

Deficiency causes the potentially fatal disease scurvy, characterized by collagen breakdown leading to problems like bleeding gums, easy bruising, joint pain and poor wound healing. Populations with low intake are at risk, including smokers, the homebound elderly and alcoholics. Improving vitamin C status reverses deficiencies.

Significantly high supplement doses like 2-3 grams may cause side effects including diarrhea, nausea, abdominal cramps, headache, insomnia and kidney stones in some people. But these amounts far exceed normal dietary C intake.

Dietary Sources

The RDI for adults is 75 to 90 mg per day. Some foods providing more than the daily requirement per serving include:

  • Citrus fruits
  • Berries
  • Kiwi
  • Broccoli
  • Leafy greens
  • Sweet peppers
  • Potatoes
  • Tomatoes
  • Winter squash butternut and acorn)

Vitamin D

Overview and Functions

Vitamin D represents a group of fat-soluble compounds including D2 (ergocalciferol from plants) and D3 (cholecalciferol from animal sources and sunlight). Often called the “sunshine vitamin”, our skin produces vitamin D when exposed to UV light. Either form then undergoes conversion to the active form calcitriol.

Vitamin D helps regulate calcium and phosphorous absorption and metabolism to support bone health and density. It also assists bodily processes including:

  • Cell growth and communication
  • Muscle and nerve function
  • Immunity by stimulating antimicrobial proteins
  • Fighting inflammation
  • Heart and lung health
  • Brain development and cognition

Deficiency and Toxicity

Inadequate sun exposure and low dietary intake can lead to low D levels. Symptoms like bone/muscle pain and weakness, fatigue, low mood, poor immunity and slow healing of wounds indicate deficiency. Those at highest risk for problems include breastfed infants, the elderly, obese people and those with digestive disorders.

Consuming very high amounts of vitamin D supplements over long periods can be toxic, causing high blood calcium (hypercalcemia), bone and tissue calcification, kidney stones, nausea and poor appetite. But it is extremely difficult to reach toxic levels from sun exposure and foods alone.

Dietary Sources

The RDI for D is 600 IU (15 mcg) up to age 70 and 800 IU (20 mcg) for older adults. Some dietary sources include:

  • Fatty fish like salmon, tuna and mackerel
  • Fish liver oils
  • Egg yolks
  • Mushrooms
  • Milk and dairy products
  • Fortified milk alternatives and juices
  • Beef liver
  • Fortified cereals

Vitamin K

Overview and Functions

Vitamin K is a fat-soluble nutrient that exists naturally in two forms: K1 (phylloquinone) from plant foods and K2 (menaquinone) from animal sources. This vitamin allows for proper blood clotting and coagulation by helping produce prothrombin and other clot-forming factors.

It also helps bind calcium to bones and teeth, preventing breakdown and loss. Other roles include protecting heart health, aiding energy production in cells and enabling activation of K-dependent proteins.

Deficiency and Toxicity

Deficiency impairs blood clotting, increasing risk for uncontrolled bleeding and bruising. Newborns, those taking blood thinners and people with absorption disorders like celiac disease are most prone to deficiency. Adding more K-rich foods or supplements can prevent and correct low levels before bleeding problems occur.

Consuming very large doses from supplements may possibly lead to symptoms like anemia, liver damage and jaundice. But vitamin K from regular diets does not pose toxicity concerns.

Dietary Sources

The RDI for vitamin K is 120 mcg daily for men and 90 mcg for women. Rich dietary sources include:

  • Leafy greens like kale, spinach and turnip greens
  • Broccoli
  • Lentils
  • Soybeans
  • Eggs yolks
  • Strawberries
  • Prunes
  • Liver
  • Fermented foods


Overview and Functions

The most abundant mineral in the body, calcium plays vital structural roles in bones and teeth, comprising up to 99% of their mineral content. This electrolyte also assists bodily processes like:

  • Muscle contraction
  • Nerve transmission
  • Hormone and enzyme production
  • Blood clotting
  • Heart rhythm
  • Fluid balance

Ensuring sufficient intakes, especially during developmental years can help achieve peak bone mass by age 30 to reduce osteoporosis risk later on. Consuming calcium with vitamin D enhances absorption and utilization.

Deficiency and Toxicity

Inadequate calcium over time can lead to weakened bones that become prone to fractures and deformities later on. Children may experience impaired growth and rickets. Deficiency also causes muscle cramping, numbness and overactive nerves. Those prone to low levels include postmenopausal women, vegetarians, lactose intolerant people, alcoholics and female athletes.

Getting extremely high amounts from supplements long-term on the other hand may increase risk for prostate cancer and heart disease. Tolerable upper limits range between 2,000mg to 3,000mg daily, depending on age. Amounts in normal diets do not raise toxicity concerns.

Dietary Sources

The RDI for most adults is 1,000 to 1,200 mg calcium daily. Some rich dietary sources include:

  • Dairy products like milk, yogurt and cheese
  • Canned fish with bones like sardines
  • Certain leafy greens
  • Soy foods like tofu
  • Blackstrap molasses
  • Almonds and almond butter
  • Calcium-set tofu
  • Fortified milk alternatives and juices


Overview and Functions

Chromium is an essential trace mineral that primarily exists in two forms ??? trivalent chromium (Cr3+) found in food and supplements and hexavalent chromium (Cr6+) often from industrial pollution. Trivalent chromium acts as a vital cofactor for insulin activity, helping transport glucose into cells for energy production.

This key micronutrient also assists protein, carb and lipid metabolism processes. Ensuring adequate chromium intake can help stabilize appetite, build muscle mass and prevent age-related declines in brain function.

Deficiency and Toxicity

Low levels may contribute to insulin resistance, impaired glucose tolerance, fatigue, anxiety and nerve damage over time. Groups most vulnerable to deficiency include pregnant or breastfeeding women, adolescents, strict vegetarians and diabetics. Taking supplements may benefit those at risk when diet proves insufficient.

Breathing in too much toxic hexavalent chromium can damage the nose and lungs however. While trivalent chromium from foods and supplements does not pose toxicity concerns even in larger doses due to poor absorption rates.

Dietary Sources

No RDI exists for chromium due to insufficient data. But adequate intake is set at 25 mcg for women up to age 50 – rising to 30 mcg during pregnancy and 35 mcg for men. Some dietary sources rich in trivalent chromium include:

  • Broccoli
  • Grape juice
  • Whole grain products
  • Raw onions
  • Lean meats
  • Potatoes
  • Oysters
  • Nuts, seeds and legumes
  • Turkey, chicken and eggs
  • Some wines and beers


Overview and Functions

The essential mineral copper assists the activity of enzymes involved in energy production, nerve transmission, collagen formation, iron metabolism, skin pigmentatios and health maintenance. Ensuring adequate copper intakes can help prevent risks for heart disease, osteoporosis and anemia. Other key functions include:

  • Forming red blood cells
  • Utilizing vitamin C
  • Supporting antioxidant and immune defenses
  • Preserving nerve fibers
  • Aiding neurotransmitter synthesis

Deficiency and Toxicity

Deficiency frequently results from nutritional, digestive and metabolic disorders that reduce absorption like gastric bypass surgery. Symptoms include weakness, pain and skin sores. Higher needs during pregnancy, rapid growth periods, infection and trauma also increase risk for low copper levels. Consuming more copper-rich foods prevents shortfalls.

Ingesting high levels from contaminated water and foods or supplements may cause toxicity however. Potential symptoms include nausea, abdominal pain, yellow skin/eyes and liver damage. But average diets contain safe copper levels.

Dietary Sources

The RDI for adults is 900 mcg of copper daily. Some food sources rich in this mineral include:

  • Organ meats like liver
  • Seafood, especially shellfish
  • Seeds like flax, sesame and pumpkin
  • Soy products
  • Legumes like lentils and beans
  • Nuts like cashews and almonds
  • Mushrooms
  • Avocados
  • Leafy greens
  • Ready-to-eat cereals
  • Cocoa powder
  • Blackstrap molasses


Overview and Functions

The mineral fluoride primarily protects against dental caries and cavities by preventing erosion of tooth enamel. When teeth take up fluoride from foods, drinking water and dental products, it helps repair early decay and makes enamel more resistant to acid corrosion. Fluoride may also offer bone-strengthening benefits.

However, excess accumulation can negatively impact bone and tooth development in children. For this reason, fluoride levels in drinking water and dental products get carefully monitored.

Dietary Sources

While no dietary recommendations exist for fluoride, important food sources include:

  • Fluoridated drinking water
  • Tea leaves
  • Marine fish
  • Raisins and dried apricots

Many communities add fluoride to municipal water sources as well to help prevent tooth decay. Using fluoridated toothpastes and mouth rinses also increases exposure.


Overview and Functions

The essential mineral iodine primarily enables thyroid gland production of hormones triiodothyronine (T3) and thyroxine (T4) which help regulate growth, development, metabolism and reproductive health. Other roles include:

  • Aiding cognitive development in fetuses and infants
  • Maintaining energy levels
  • Supporting healthy skin and hair

Sea vegetables and plants grown in iodine-rich soils usually serve as prime dietary sources. As such, deficiency remains a concern for those living in inland areas eating mostly land-based produce.

Deficiency and Toxicity

Inadequate iodine causes hypothyroidism which results in symptoms like fatigue, dry skin, swelling, weight gain, impaired brain development and goiter (enlarged thyroid gland). However, getting excess iodine can also disrupt thyroid function. So supplementation requires monitoring to avoid going too far in either direction.

Dietary Sources

The RDI for adult iodine intake stands at 150 mcg per day, while pregnant/breastfeeding women require more at around 250 mcg. Some dietary sources naturally rich in iodine include:

  • Seafood
  • Iodized salt
  • Sea vegetables
  • Dairy products
  • Eggs
  • Turkey, chicken and strawberries also contain small amounts

Many countries iodize table salt to prevent hypothyroidism and associated deficiencies from becoming widespread public health concerns.


Overview and Functions

The mineral iron has primary importance due to it’s role in forming hemoglobin to supply oxygen throughout bodily tissues. This component of red blood cells also enables muscle and brain function. Non-heme iron from plant foods needs vitamin C for best absorption. Key roles of iron include:

  • Binding and releasing oxygen as part of hemoglobin
  • Facilitating several enzymes in energy metabolism
  • Aiding immune system function
  • Supporting physical and mental performance
  • Preventing anemia

Nearly two-thirds of iron in the body binds with hemoglobin proteins to carry out vital roles in respiration and activity.

Deficiency and Toxicity

Low iron intake coupled with bleeding causes iron deficiency anemia, resulting in abnormal tiredness, headaches, dizziness, pale skin, brittle nails and inflammation around the mouth. Supplementing with ferrous sulfate or consuming more heme iron from meat and vitamin C from produce reverses deficiency.

Conversely, inheriting hemochromatosis which accumulation excess iron in organs can damage their tissues over time and sometimes lead to diabetes, liver cancer or heart failure. People with this condition must monitor and restrict dietary iron. But such problems do not occur in healthy individuals.

Dietary Sources

The RDI is 8 mg for men and 18 mg for reproductive age women, which includes an additional 10 mg for iron lost through menstruation. Some foods rich in highly bioavailable heme iron include:

  • Organ meats like liver
  • Beef
  • Lamb
  • Seafood

Non-heme plant sources like lentils, spinach, quinoa and nuts contain iron as well but get utilized less effectively. Pairing these with vitamin C however improves absorption.


Overview and Functions

As the fourth most abundant mineral in the body, magnesium supports hundreds of vital metabolic reactions, including muscle and nerve transmission, blood glucose control, protein production, bone development and DNA synthesis. Roughly half of total magnesium gets deposited into bones and soft tissues, while the rest maintains balance between fluids and cells.

Key roles include helping:

  • Regulate calcium, sodium, potassium and other vital nutrients
  • Assist bodily energy production and antioxidant function
  • Control blood pressure
  • Stabilize heart rhythm
  • Maintain normal brain and nerve function

Deficiency and Toxicity

Significantly low magnesium intake from dietary sources is rare, but can cause risks like high blood pressure, arrhythmias, migraines, fatigue and impaired cellular metabolism over time if unchecked. Obtaining at least 400-420 mg daily prevents shortfalls.

Hypermagnesemia from getting too much magnesium on the other hand usually only affects those with kidney disorders. Signs may include diarrhea, nausea, urine retention, low blood pressure and irregular heartbeat. But toxicity will not occur from naturally magnesium-rich foods.

Dietary Sources

The RDI for magnesium is 400-420 mg per day for most healthy adults. Some foods providing excellent amounts include:

  • Dark leafy greens
  • Nuts and seeds
  • Legumes like beans and lentils
  • Soy products like tofu and edamame
  • Avocados
  • Bananas
  • Fatty fish
  • Dark chocolate

Whole grains, fruits, meat and dairy also supply smaller amounts that add up.


Overview and Functions

Manganese serves as an essential cofactor for enzymes involved in bone/cartilage formation, metabolism, digestion and antioxidant function. The mineral also assists motor control and brain health. Other key roles include:

  • Aiding nutrient absorption
  • Facilitating collagen production
  • Supporting tissue growth and repair
  • Enabling enzymes for antioxidant protection

Roughly 40% of dietary manganese gets absorbed by the human body to carry out tasks crucial for development, metabolism, reproduction and health overall.

Deficiency and Toxicity

Overt manganese deficiency rarely occurs without an underlying health disorder causing poor absorption or digestion because trace amounts abundantly occur in foods. But adequate intake ensures sufficient quantities to prevent risks like impaired growth, glucose intolerance, hearing loss and more.

Getting too much manganese primarily from contaminated well water or long range occupational exposures can potentially damage the brain and nerves however. But food sources pose no toxicity threat even in generous amounts.

Dietary Sources

The AI level for manganese stands at 2.3 mg per day for men and 1.8 mg for women. Some prime food sources rich in this mineral include:

  • Whole grains and cereal products
  • Nuts like pecans and almonds
  • Legumes including beans, peas and soy foods
  • Seeds like pumpkin and flax
  • Leafy green veggies
  • Tea
  • Cocoa powder
  • Dried fruits


Overview and Functions

As a trace element, molybdenum occurs in soil and gets taken up into plant foods. The mineral then serves vital roles in humans once consumed, almost exclusively as part of metalloenzyme compounds. These assist bodily processes including:

  • Sulfite detoxification
  • Uric acid formation
  • Iron utilization
  • Carbohydrate and fat metabolism
    Molybdenum further enables adequate growth and development, reproduction and neurological health.

Deficiency and Toxicity

Deficiency rarely develops from dietary causes alone since minimal amounts abundantly occur in everyday foods. But inadequate absorption attributable to medical conditions can cause buildup of sulfite toxicity leading to brain dysfunction. Treating underlying disorders or molybdenum supplementation solves shortfalls.

Conversely, overexposure through contaminated water or prolonged occupational contact may result in gout-like pains, diarrhea, anemia and severe neurological damage in isolated cases. But dietary molybdenum from common foods does not cause harm due to efficient regulation by the body.

Dietary Sources

No RDI exists for molybdenum since clear deficiency or toxicity signs are very rare. But the adequate intake level is set at 45 mcg for adults. Some foods rich in this mineral include:

  • Legumes like peas, lentils and beans
  • Nuts like almonds and peanuts
  • Whole grains
  • Leafy green vegetables
  • Milk and cheese


Overview and Functions

Second only to calcium in the body, phosphorus makes up 1% of total body weight. Over 80% gets deposited in bones and teeth alongside calcium to create a solid mineral structure. Phosphorus performs many other jobs as well including:

  • Forming cell membranes
  • Assisting protein production
  • Supporting nutrient absorption
  • Aiding kidney function
  • Controlling pH balance

This mineral also helps the body store energy, use vitamins and minerals and repair tissues and cells.

Deficiency and Toxicity

Low levels typically only occur in alcoholics, malnourished people and those taking certain prescription drugs that impair phosphorus absorption. Overt deficiency can cause bone pain, increased fractures, numbness and heart issues in severe cases. Consuming phosphorus-rich foods prevents shortfalls.

Surprisingly, toxicity may affect more people than deficiency due to overconsumption of soda and processed snacks loaded with phosphoric acid preservatives. But supplements and natural phosphorus sources do not pose this risk. Signs involve kidney damage and mineral imbalances inhibiting bone health.

Dietary Sources

The RDI for phosphorus is 700 mg for adults per day. Some abundant food sources include:

  • Meat, poultry and fish
  • Dairy products
  • Nuts, seeds and soy foods
  • Whole grains
  • Chocolate
  • Some soda beverages

Lentils, corn, broccoli and garlic also provide smaller but useful amounts.


Overview and Functions

Vital for heart, muscle and nerve signaling functions, potassium performs many crucial roles as the chief electrolyte inside cells. Yet only around 2% of the body’s potassium stores get found outside cells, underscoring the importance of continual dietary intake. Proper potassium levels carefully control critical activities like:

  • Regulating fluids
  • Transmitting nerve signals
  • Making proteins
  • Building muscle
  • Releasing energy from nutrients

Relatedly, this mineral influences blood pressure, heart rhythm and oxygen delivery while aiding essential cellular processes.

Deficiency and Toxicity

Deficiency does not typically result from low dietary potassium alone but rather from excessive loss such as during repeated vomiting, chronic diarrhea or certain kidney disorders. Obtaining adequate intake through fruits, veggies and other potassium-rich foods can prevent low levels however.

Conversely, getting too much supplemental potassium can interfere with heart signals and prove fatal without urgent treatment. Impaired kidneys cannot excrete excess potassium properly leading to hyperkalemia, especially in those taking related medications. But high food-based intake poses no concerns for healthy people.

Dietary Sources

The potassium RDI for adults is 4,700 mg daily spread through meals and snacks. Some top sources include:

  • Bananas and plantains
  • Dried fruits like prunes and raisins
    Potatoes and sweet potatoes with skin
    Tomatoes and tomato sauce
  • Oranges and orange juice
  • Leafy greens
  • Beans, lentils and peas
  • Salmon, tuna and other fatty fish
  • Milk and yogurt


Overview and Functions

As one of the body’s main electrolytes, sodium regulates fluid balance and blood volume and enables muscle and nerve function. Along with potassium, this abundant mineral also controls critical processes such as:

  • Regulating blood pressure
  • Supporting oxygen and nutrient transport
  • Allowing glucose absorption
  • Facilitating nerve signals
  • Controlling pH levels

Sodium works together with several other electrolytes to maintain homeostasis. Getting sufficient amounts prevents muscle cramping and cardiovascular strain.

Deficiency Toxicity

Low sodium levels rarely occur naturally but may result from excessive sweating, vomiting, diarrhea or medications like diuretics or laxatives depleting bodily stores. Symptoms range from fatigue, nausea and mental impairment to coma and death if left uncorrected. However, most people consume excess sodium that can raise blood pressure.

While sodium deficiency is uncommon, getting excessive intake contributes to high blood pressure, fluid retention and strain on the kidneys, heart and blood vessels in some people. Current guidelines advise limiting added salt and salty processed foods to avoid going over the tolerable upper limit of 2,300 mg per day.

Dietary Sources

The minimum RDI is around 500 mg sodium daily, but most people get 1,500 to 2,300 mg per day. Key dietary sources include:

  • Table salt and salty condiments
  • Canned foods and pickled items
  • Cured meats like bacon, sausage and ham
  • Cheese, olives, pretzels and salted nuts
  • Egg yolks and baked goods
  • Fast foods and frozen meals
  • Salted butter and soy sauce


Overview and Functions

Found in every cell, zinc acts as an essential component of over 300 enzymes and compounds vital to bodily processes like:

  • Immunity
  • Protein and DNA synthesis
  • Growth and development
  • Wound healing
  • Thyroid function
  • Metabolism of carbs, lipids and vitamins

Ensuring adequate zinc intake maintains taste, vision, cognition, fertility and defense against illness. This mineral also has antioxidant properties that inhibit free radical formation.

Deficiency and Toxicity

Deficiency often results from poor diet, alcoholism, digestive disorders, chronic illness, diuretics or other causes impairing absorption and metabolism. Symptoms include increased colds/flu, chronic wounds, stunted growth, diarrhea, eye problems and hair loss. Those at risk for low zinc levels, especially vegetarians and older adults, can benefit from supplements.

Consuming extremely high zinc doses from supplements long term can possibly lead to copper deficiency and neurological issues. But food sources provide zinc safely, even in generous amounts. Phytates that block zinc absorption somewhat limit risks for overconsumption.

Dietary Sources

The RDI stands at 11 mg per day for men and 8 mg for non-pregnant women. Some foods rich in highly bioavailable zinc include:

  • Meat
  • Shellfish, especially oysters
  • Dairy products
  • Eggs
  • Legumes like chickpeas
  • Nuts and seeds
  • Whole grains

This covers all the key vitamins and minerals needed for optimal health and functionality. Focusing on getting sufficient amounts from wholesome dietary sources can help maintain wellbeing and reduce disease risks.


Why do we need vitamins and minerals?

Vitamins and minerals serve vital roles in all bodily functions including cell metabolism, tissue growth and repair, enzyme reactions, immune support and converting food into energy. Getting adequate amounts prevents deficiency and reduces risks of chronic disease.

What are the best food sources of vitamins?

Fruits, vegetables, whole grains, beans, lentils, nuts, seeds and animal foods like meat, fish, eggs and dairy provide the widest variety of essential vitamins. Orange/red produce contains the most vitamin A and C. Leafy greens offer vitamins K, E, folate and more.

What vitamins support healthy bones?

Vitamins D, K, C and B complex help optimize calcium absorption and bone mineralization. Vitamin D also aids proper bone remodeling. Getting enough of these from sources like salmon, yogurt and leafy greens as youths prevents osteoporosis later on.

Do adults need to take multivitamins?

Most healthy adults can obtain all necessary vitamins from eating balanced diets high in diverse plant and animal foods. However, those at risk for deficiency due to restricted diets, digestive issues or age-related absorption declines can benefit from standard multivitamins per medical advice.

What minerals do vegans need to supplement in their diets?

Vegans who avoid all animal products require reliable plant-based sources of iron, zinc, iodine, selenium and especially vitamin B12 to meet health needs. Taking supplements helps provide sufficient quantities when diet alone falls short.


Vitamins and minerals serve as essential micronutrients that our bodies require from food sources and supplementation in order to function optimally. Though only needed in small quantities, they enable hundreds of vital bodily processes that we depend on to thrive.

As outlined in this extensive A to Z guide, each vitamin and mineral plays crucial roles related to metabolism, tissue growth/repair, bone health, breathing, cognition, immune defense and protecting against chronic disease. Getting adequate intake of these nutrients ensures normal development, achievement of peak bone mass, robust cellular function, proper neurotransmitter balance, adequate detoxification and more throughout life.

Certain groups like growing children, teens, pregnant women and older adults have increased needs for select micronutrients. Vegans and those with digestive issues, alcoholism or certain medical conditions may also require supplementation to prevent potential deficiencies.

Read More

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Mysteries of Vitamin B12: A Guide to Health and Wellness

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Dr. Kishore Kumar (General Surgeon)
Dr. Kishore Kumar (General Surgeon)
Dr. Kishore Kumar is a General Surgeon, Proctologist, Vascular Surgeon, Laparoscopic Surgeon and Laser Specialist,

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