Everything you need to know about vitamin & minerals for good health

It’s not breaking news that vitamins and minerals are essential to good health.

Most of us have been told that since we were in diapers.

Heck, even Lucky Charms brags about being “fortified with 12 essential vitamins and minerals.” So they must be important!

But why, exactly?

How many vitamins and minerals are there, and what do they actually do? What foods contain them? And if you have a deficiency, how do you know?

Also, is there more nutrition in a grape-flavored Fred Flinstone chewable vitamin than in an orange-flavored Wilma?

(No.)

We’ve got your answers.

In this article, you’ll learn:

What vitamins and minerals are
Why we need them to stay healthy
How you absorb and use them

Plus, we’ll give you a complete list of all the vitamins and minerals, what they do, how much you need, signs of deficiency, and what foods to get them from.

If you’re only interested in a specific vitamin or mineral, use the list below to jump right to it.

Otherwise, scroll on by these quick links, and we’ll dive into everything you need to know about vitamins and minerals.

(For more deep insights—about nutrition and beyond—check out our FREE weekly newsletter, The Smartest Coach in the Room.)

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What are vitamins and minerals?

We know that vitamins and minerals come from our diet and also supplements, but what are they?

Well, they’re molecules. Or—in the case of minerals—elements.

But there are also a few other (more practical) things we know…

Vitamins and minerals prevent disease, but also help us feel energetic and healthy.

Years ago, medical professionals noticed that certains symptoms and diseases seemed to be directly related to food intake.

Some people got sick even when they were eating adequate calories and protein while others didn’t. Scientists determined that the types of food people ate—or more accurately, didn’t—seemed to be the difference.

The most famous example (which you’ve no doubt heard before): Sailors on long sea voyages were prone to developing scurvy—unless they ate citrus fruit. Turns out, all it took was the occasional lemon slice to keep their bleeding gums at bay.

From that and other examples, scientists reasoned that there must be important compounds in foods that prevent—and perhaps even cure—diseases.

These compounds were vitamins and minerals.

Vitamins and minerals come from food (and maybe supplements).

Some nutrients can be created in the body—for example, some of the B vitamins can be made by bacteria in the gut—but some can’t.

So we have to get our vitamin and mineral requirements from nutritious foods (or supplements), eaten regularly.

Whole, minimally-processed foods like vegetables, fruits, nuts, seeds, legumes, whole grains, dairy, and animal proteins are rich sources of vitamins and minerals. Our bodies rely on them to support normal physical functions like digestion, reproduction, growth, and energy production.^1,2

If you don’t consume enough of a vitamin or mineral, you’ll develop a deficiency.

Sometimes, if diet quality or calorie intake is low, or digestion and absorption is compromised, we don’t get enough of a vitamin or mineral to meet our body’s needs.

If this goes on long enough, we can develop a deficiency.

Specific vitamin and mineral deficiencies will cause specific symptoms (more on that below), and can even cause or exacerbate chronic health conditions.

Nutrient deficiencies are common. Over 30 percent of Americans have some kind of micronutrient deficiency.³

That’s a clinical deficiency we’re talking about. Clinical deficiencies are often the endpoint of a prolonged vitamin or mineral insufficiency and usually have pretty obvious symptoms.

However, milder forms of deficiency, often of multiple micronutrients, are much more common.^4,5 These milder forms of deficiency are called subclinical deficiencies.

For example, it’s estimated that about 20 percent of the world has a subclinical magnesium deficiency. In certain populations—like people with poorly-controlled type 2 diabetes—it might be as high as 75 percent.⁶

Subclinical deficiencies are harder to recognize, as they don’t always have clear, predictable symptoms. But it’s likely that suboptimal levels of any vitamin or mineral—or multiple micronutrients—will have negative effects on the body. (Even if there’s no obvious outward symptoms.)

Here are the most common deficiencies in the US, according to the most recent National Health and Nutrition Examination Survey (NHANES)⁷:

Micronutrient	Prevalence of Clinical Deficiency
Vitamin B6	11% of the total population
Iron	10% of females aged 12-49, and 7% of children aged 1-5
Vitamin D	9% of the total population (31% of non-hispanic Blacks)
Vitamin C	6% of people over the age of 6
Vitamin B12	2% of the total population

What’s more, deficiencies are particularly common among certain populations:

The elderly, who may have trouble preparing, chewing, or digesting foods
Women (aged 19-50), particularly if pregnant or breastfeeding
Athletes, who have higher nutrient requirements because of the extra demands on their body
People with darker skin tones, who may be particularly at risk for vitamin D deficiency⁸ (overall, many people—about 24 percent of Americans⁹, 37 percent of Canadians¹⁰, and 40 percent of Europeans¹¹—have suboptimal levels of vitamin D¹²)
Chronic dieters or people who struggle with disordered eating, due to restricting specific food groups or calories overall
People with lower socioeconomic status, who may have challenges accessing fresh, nutritious foods

So, now that we know how important vitamins and minerals are, let’s find out more about what each nutrient does, and which foods contain them.

(If you want to jump over the details here, and get to practical advice for optimizing your vitamin and mineral intake, go ahead and click here.)

Vitamins

Vitamins serve a variety of roles in the body. One of the most important things they do is when they act as coenzymes.

Coenzymes enhance the action of enzymes and help carry out reactions in the body, for example, contracting a muscle.

Vitamins are either fat-soluble or water-soluble.

Fat-soluble vitamins are absorbed with dietary fat. If we don’t eat enough dietary fat, we don’t properly absorb these vitamins. That’s why a very low-fat diet can lead to deficiencies of fat-soluble vitamins.

We can excrete fat-soluble vitamins through our poop, but we can also store them in our fatty tissues. Fatty tissues include things like body fat stores, but also cell membranes, which are made up of fat. Because we store them, we don’t necessarily have to eat these vitamins every day.

Water-soluble vitamins don’t require fat to be absorbed. However, they’re also generally not stored in high amounts in the body and can be excreted in the urine. As a result, we need to eat them more often.

Water-soluble vitamins

Vitamin B1 (Thiamine)

Vitamin B1 is involved in producing energy, as well as synthesizing DNA and RNA, the nucleic acids that carry our genetic material.

Vitamin B1 Deficiency: Symptoms include burning feet, weakness in extremities, rapid heart rate, swelling, lack of appetite, nausea, fatigue, and digestive problems.

Toxicity: None known.

Vitamin B1 Food Sources: Sunflower seeds, asparagus, lettuce, mushrooms, black beans, navy beans, lentils, spinach, peas, pinto beans, lima beans, eggplant, Brussels sprouts, tomatoes, tuna, whole wheat, soybeans

Vitamin B2 (Riboflavin)

Vitamin B2 helps produce red blood cells and metabolize toxins in the liver. (It’s also what turns your pee bright yellow when you take a multivitamin!)

Vitamin B2 Deficiency: Symptoms include cracks, fissures and sores at corner of mouth and lips, dermatitis, conjunctivitis, light sensitivity (photophobia), inflammation in the mouth, anxiety, loss of appetite, and fatigue.

Toxicity: Very rare. Excess supplementation can cause liver damage.

Vitamin B2 Food Sources: Almonds, soybeans / tempeh, mushrooms, spinach, whole wheat, yogurt, mackerel, eggs, liver

Vitamin B3 (Niacin)

Vitamin B3 plays a role in repairing DNA, keeping nerves healthy, and controlling cholesterol levels.

Vitamin B3 Deficiency: Symptoms include dermatitis, diarrhea, dementia, and inflammation of the stomach.

Toxicity: Very rare from foods. Supplemental nicotinic acid (a form of niacin) may cause skin flushing, itching, impaired glucose tolerance and digestive upset. Taking high doses for months at a time can cause liver cell damage.

Vitamin B3 Food Sources: Mushrooms, asparagus, peanuts, brown rice, corn, green leafy vegetables, sweet potato, potato, lentil, barley, carrots, almonds, celery, turnips, peaches, chicken meat, tuna, salmon

Vitamin B5 (Pantothenic acid)

Vitamin B5 helps to form acetyl-CoA, an important molecule involved in energy production. It also helps keep skin healthy.

Vitamin B5 Deficiency: Very unlikely. Only in severe malnutrition may one notice tingling in feet.

Toxicity: Possible nausea, heartburn, and diarrhea with high-dose supplements.

Vitamin B5 Food Sources: Broccoli, lentils, split peas, avocado, whole wheat, mushrooms, sweet potato, sunflower seeds, cauliflower, green leafy vegetables, eggs, squash, strawberries, liver

Vitamin B6 (Pyridoxine)

Vitamin B6 is involved in glycogen breakdown, nervous and immune system function, and the formation of neurotransmitters and steroid hormones.

Vitamin B6 Deficiency: Symptoms include inflammation of the skin and digestive system, sleeplessness, confusion, nervousness, depression, irritability, and anemia.

Toxicity: High doses of supplemental vitamin B6 may result in painful neurological symptoms.

Vitamin B6 Food Sources: Whole wheat, brown rice, green leafy vegetables, sunflower seeds, potato, garbanzo beans, banana, trout, spinach, walnuts, peanut butter, tuna, salmon, lima beans, chicken

Vitamin B7 (Biotin)

Vitamin B7 is involved in energy production, as well as DNA replication and transcription.

Biotin Deficiency: Very rare in humans. Note that raw egg whites contain avidin, a protein that binds to biotin and prevents its absorption. Regularly eating raw egg whites can cause biotin deficiency.

Toxicity: Not known.

Biotin Food Sources: Green leafy vegetables, most nuts, whole-grain breads, avocado, raspberries, cauliflower, carrots, papaya, banana, salmon, eggs

Vitamin B9 (Folate / Folic acid)

Folate helps to form new proteins and is also involved in fetal development.

Folate refers to the naturally occurring form found in foods. Folic acid is the synthetic form of the vitamin, used in most supplements and fortified foods.

Vitamin B9 Deficiency: Anemia (macrocytic / megaloblastic), low white blood cells (leukopenia), low blood platelets (thrombocytopenia), weakness, weight loss, cracking and redness of the tongue and mouth, and diarrhea. In pregnancy, there is a risk of low birth weight, preterm delivery, and neural tube defects.¹³

Toxicity: None from food. Large doses of supplemental folic acid can mask an underlying vitamin B12 deficiency.

Vitamin B9 Food Sources: Green leafy vegetables, asparagus, broccoli, Brussels sprouts, citrus fruits, beans and legumes, whole grains, green peas, avocado, peanuts, organ meats

Vitamin B12 (Cobalamin)

Vitamin B12 is involved in DNA synthesis, and also helps to form and maintain healthy blood and nerve cells. Vitamin B12 needs “intrinsic factor” (a compound secreted by the stomach during digestion) to be absorbed. We can store decades worth of this vitamin in our body—but it should still be consumed regularly.

Vitamin B12 Deficiency: Symptoms include pernicious anemia, neurological problems, mouth inflammation. Strict vegans and plant-based eaters may be more at risk.¹⁴

Toxicity: Extremely rare, even with supplementation. Only a small amount is absorbed orally, thus the potential for toxicity is low.

Vitamin B12 Food Sources: Liver, trout, salmon, tuna, haddock, egg, dairy. Vitamin B12 isn’t found in plant foods.

Choline

Choline is a nutrient often grouped together with the B vitamins. It’s involved in building cell membranes and neurotransmitters (like acetylcholine, an essential neurotransmitter for muscle impulses). It may also help lower inflammation.

Choline Deficiency: Symptoms include problems with thinking and memory, muscle and nervous tissue damage, or even liver and kidney disease.

Toxicity: Toxicity is rare from food, but excess supplementation may lead to low blood pressure.

Choline Food Sources: Colorful fruits and veggies, organ meats

Vitamin C (Ascorbic acid)

Vitamin C is probably most famous for its role in supporting the immune system. However, it also helps build collagen, keeping skin and joints healthy; synthesize norepinephrine, an adrenal hormone; and metabolize cholesterol.

Vitamin C Deficiency: Symptoms include bruising, lethargy, dental cavities, tissue swelling, dry hair, skin, and eyes, bleeding and infected gums, hair loss, joint pain, delayed wound healing, and bone fragility. Long-term deficiency results in scurvy.

Toxicity: Possible problems with very large vitamin C doses include diarrhea and a higher risk of kidney stones.

Vitamin C Food Sources: Most (fresh, raw) colorful fruits and vegetables

Fat-soluble vitamins

Vitamin A (Retinoids and carotenoids)

The vitamin A family includes animal sources (retinol, retinal, and retinoic acid) and plant sources (carotenoids). They help maintain eye health, and support immune function and wound healing.

Vitamin A Deficiency: Difficulty seeing in dim light and rough/dry skin.

Toxicity: Hypervitaminosis A is caused by consuming excessive amounts of preformed vitamin A (found in supplements but also in animal products, like liver). Preformed vitamin A is rapidly absorbed and slowly cleared from the body. Nausea, headache, fatigue, loss of appetite, dizziness, and dry skin can result. Excess intake while pregnant can cause birth defects. Carotenoid toxicity is rare.

Vitamin A Food Sources: Liver, egg yolks, carrots, sweet potato, pumpkin, green leafy vegetables, squash, cantaloupe, bell pepper, beets

Vitamin D (Ergocalciferol / cholecalciferol)

Vitamin D is actually a group of prohormones (hormone precursors). The plant form of vitamin D is called ergocalciferol (vitamin D₂) and the animal form is called cholecalciferol (vitamin D₃). Vitamin D helps with calcium absorption, immune system function, and regulating glucose tolerance.

Vitamin D Deficiency: In children a vitamin D deficiency can result in rickets, deformed bones, delayed growth, and soft teeth. In adults a vitamin D deficiency can result in low bone density and tooth decay. People with darker skin are at higher risk of deficiency.

Toxicity: We can’t get too much vitamin D from the sun; only excess supplementation. Too much vitamin D will elevate blood calcium levels and may cause loss of appetite, nausea, vomiting, excessive thirst, excessive urination, itching, muscle weakness, joint pain, and calcification of soft tissues.

Vitamin D Food Sources: Although it’s not a food, the most available and “natural” source of Vitamin D is from sunlight exposure. It’s also in fortified foods, mushrooms, salmon, mackerel, sardines, tuna, shrimp, egg yolks, and beef liver.

Learn more about Vitamin D here: All About Vitamin D

Vitamin E (tocopherols and tocotrienols)

Vitamin E is not actually a single vitamin, but a family of eight compounds: four tocopherols and four tocotrienols. The vitamin E family are potent antioxidants, and are also involved in cell-to-cell communication.

Vitamin E Deficiency: Symptoms include muscle weakness, impaired vision, acne, red blood cell damage, and problems with muscle coordination (ataxia).

Toxicity: There is a potential for impaired blood clotting.

Vitamin E Food Sources: Green leafy vegetables, nuts and seeds, olives, avocado

Vitamin K

Vitamin K is a family of vitamins that includes vitamin K₁ (the plant-based form) and vitamin K₂ (the animal-based form). Vitamin K is involved in normal blood clotting and also plays a role in keeping bones healthy.

Vitamin K Deficiency: Tendency to bleed or hemorrhage, and anemia.

Toxicity: May interfere with blood-thinning medications No known toxicity with high doses.

Vitamin K Food Sources: Broccoli, green leafy vegetables, parsley, watercress, asparagus, Brussels sprouts, green beans, green peas

Minerals

Our bodies and the foods we eat contain minerals. Most minerals are considered essential (meaning: we need to get them regularly from our diet).

However, certain molecules found in food can change our ability to absorb minerals. This includes compounds like phytates (found in grains) and oxalates (found in spinach and rhubarb), both of which inhibit mineral absorption. Proper cooking can reduce these compounds, and thus, increase mineral absorption.

Minerals are categorized as macrominerals or microminerals.

Macrominerals are required in larger amounts and include minerals like magnesium, calcium, and potassium.

Microminerals are required in small or trace amounts. They include minerals such as iron, chromium, and zinc.

Macrominerals

Calcium

Calcium is the most common mineral in our body. It’s involved in muscle contraction, teeth and bone formation, and hormone secretion.

Calcium Deficiency: Long-term inadequate intake can result in low bone density, rickets, osteomalacia, and osteoporosis.

Toxicity: Will cause nausea, vomiting, constipation, dry mouth, thirst, increased urination, kidney stones and soft tissue calcification.

Calcium Food Sources: Dairy, green leafy vegetables, legumes, tofu, molasses, sardines, okra, perch, trout, Chinese cabbage, rhubarb, sesame seeds

Chloride

Chloride is involved in digestion and absorption (it helps make up hydrochloric acid in the stomach), as well as cell functioning.

Chloride Deficiency: Extremely rare, but may happen in cases of excessive fluid loss (through vomiting and/or diarrhea).

Toxicity: Not known.

Chloride Food Sources: Almost all whole foods contain chloride (e.g. fruits and vegetables, lean meats)

Phosphorus

Phosphorus is the “P” (phosphate) in “ATP”, the body’s principal form of energy. Phosphorus plays a role in energy transfer, bone formation, enzyme production, and oxygen regulation.

Phosphorus Deficiency: Very rare, except in cases of severe malnutrition.

Toxicity: Very rare.

Phosphorus Food Sources: Legumes, nuts, seeds, whole grains, eggs, fish, buckwheat, seafood, corn, wild rice

Potassium

Along with sodium, potassium helps to maintain the electrochemical gradient, which is what determines how ions move across a cell membrane.

Potassium Deficiency: Usually caused by protein wasting conditions, or excessive use of diuretics, which can cause loss of potassium in the urine. Low blood potassium can result in cardiac arrhythmias or even cardiac arrest.

Toxicity: Symptoms include tingling of extremities and muscle weakness. High dose potassium supplements may cause nausea, vomiting and diarrhea.

Potassium Food Sources: Sweet potato, tomato, green leafy vegetables, carrots, prunes, beans, molasses, squash, fish, bananas, peaches, apricots, melon, potatoes, dates, raisins, mushrooms

Magnesium

Magnesium has hundreds of roles in the body. Some of those include: Metabolizing carbohydrates and fats, synthesizing proteins and DNA, and helping to relax and repair muscles.

Magnesium Deficiency: Symptoms include muscle cramps and twitching, nausea and loss of appetite, abnormal heart rhythms, and problems with thinking, mood, and memory. Magnesium deficiency is fairly common and may also play a role in hypertension and Type 2 diabetes.

Toxicity: Excessive supplementation can lead to diarrhea (magnesium is a known laxative), impaired kidney function, low blood pressure, muscle weakness, and shortness of breath.

Magnesium Food Sources: Legumes, nuts, seeds, whole grains, dark leafy greens, potato, cacao (dark chocolate)

Sodium

Along with potassium, sodium helps to maintain an electrochemical gradient across the cell membrane. It’s also involved in regulating body fluids, blood volume, and blood pressure.

Sodium Deficiency: Symptoms include nausea, vomiting, headache, cramps, fatigue, and disorientation. Athletes who sweat a lot and hydrate without added electrolytes might be at risk of sodium imbalance.

Toxicity: Excessive intake can lead to increased fluid volume (edema), nausea, vomiting, diarrhea, and abdominal cramps. High blood sodium usually results from excessive water loss.

Sodium Food Sources: Any processed foods, whole grains, legumes, nuts, seeds, vegetables

Sulfur

Sulfur is abundant in the body and is part of three important amino acids: cysteine, methionine, and taurine. It’s also involved in liver detoxification and collagen synthesis.

Sulfur Deficiency: Deficiency is rare unless someone is on a strict, low-protein diet (or has some type of malabsorption syndrome).

Toxicity: Unlikely from food consumption.

Sulfur Food Sources: Foods high in protein (like meat, eggs, seafood), garlic, onions, cruciferous vegetables

Microminerals

Iron

Iron helps to form hemoglobin, red blood cells, and blood vessels. It’s essential for helping transport oxygen throughout the body. Dietary iron comes in two forms: heme iron (from animal foods) and non-heme (from plant foods). Consume iron with vitamin C to enhance absorption.

Iron Deficiency: Low iron can lead to anemia with small and pale red blood cells, and lowered immunity. In children, iron deficiency is associated with behavioral abnormalities. Iron deficiency is the most common deficiency in the world. Menstruating women, pregnant women, and strict plant-based eaters are most at risk.

Toxicity: Common cause of poisoning in children. Excessive intake of supplemental iron is an emergency room situation. Too much iron is associated with an increased risk of cardiovascular disease, cancer, and neurodegenerative diseases.

Iron Food Sources: Red meats, organ meats, molasses, lima beans, kidney beans, raisins, brown rice, green leafy vegetables, seaweed, pumpkin seeds, dark poultry meat, fish

Zinc

Zinc is involved in growth and development, neurological function, reproduction, immunity, cell structure and function, and more.

Zinc Deficiency: Symptoms include growth impairments, lowered immunity, skeletal abnormalities, delay in sexual maturation, poor wound healing, taste changes, night blindness and hair loss. Those at risk for deficiency include the elderly, alcoholics, vegans, and those with malabsorption.¹⁵

Toxicity: Abdominal pain, diarrhea, nausea, and vomiting. Chronically taking too much zinc can result in copper deficiency.

Zinc Food Sources: Mushrooms, spinach, sesame seeds, pumpkin seeds, green peas, baked beans, cashews, peas, whole grains, flounder, oats, oysters, chicken meat

Copper

Copper is an antioxidant and is also involved in energy production, collagen formation, and protein synthesis.

Copper Deficiency: Anemia that doesn’t respond to iron therapy, loss of hair and skin color (hypopigmentation of skin and hair is also noticed), low white blood cell count.

Toxicity: Rare. Symptoms include abdominal pain, nausea, vomiting, and diarrhea. Long-term exposure to lower doses of copper can result in liver damage.

Copper Food Sources: Mushrooms, green leafy vegetables, barley, soybeans, tempeh, sunflower seeds, navy beans, garbanzo beans, cashews, molasses, liver

Chromium

Chromium plays an important role in glucose and fat metabolism and supports the role of insulin. High-sugar diets can increase chromium excretion in urine, which means people may need more chromium.

Chromium Deficiency: Symptoms include impaired glucose tolerance and elevated circulating insulin

Toxicity: Generally limited to industrial exposure. Long-term supplement use may increase DNA damage.

Chromium Food Sources: Lettuce, onions, beef, organ meats, whole grains, potatoes, mushrooms, oats, prunes, nuts, nutritional yeast

Iodine

Iodine is essential for healthy thyroid function and the production of the thyroid hormones T₃ and T₄.

Iodine Deficiency: Impairs growth and neurological development. Deficiency can also result in decreased production of thyroid hormones and enlargement of the thyroid. (Click here for more about impaired thyroid, and what to do.)

Toxicity: Symptoms include fever, diarrhea, burning mouth / throat / stomach, and enlargement of the thyroid.

Iodine Food Sources: Sea vegetables, iodized salt, eggs, dairy

Selenium

Selenium is an antioxidant, and also plays a role in thyroid hormone metabolism.

Selenium Deficiency: Can contribute to arthritis, or juvenile cardiomyopathy (heart disease). Can also limit glutathione activity, increasing oxidation.

Toxicity: Multiple symptoms including skin problems, hair and nail brittleness, gastrointestinal disturbances, fatigue, and nervous system abnormalities.

Selenium Food Sources: Brazil nuts (but not too many—just six Brazil nuts can provide 800 mcg of selenium, exceeding the upper limit of the recommended intake!), mushrooms, barley, salmon, whole grains, walnuts, eggs

Manganese

Manganese is an antioxidant and is also involved in carbohydrate, amino acid, and cholesterol metabolism.

Manganese Deficiency: Not typically observed in humans.

Toxicity: Generally from industrial exposure.

Manganese Sources: Green leafy vegetables, berries, pineapple, lettuce, tempeh, oats, soybeans, spelt, brown rice, garbanzo beans

Molybdenum

Molybdenum plays a role in nutrient metabolism, as well as the breakdown of drugs and toxins.

Molybdenum Deficiency: Extremely rare.

Toxicity: More likely than deficiency. Still very rare.

Molybdenum Food Sources: Legumes, whole grains

3 things to know when addressing your (or your clients’) nutrient needs.

Whether you want to feel your best, or you’re helping clients do the same, making sure your basic nutrient requirements are being met is essential.

For guidance on the right amount of carbohydrates, fats, and proteins (in other words, macronutrients), check out our super cool tool: The Precision Nutrition Calculator.

You can use the above list of vitamins and minerals to get a general idea of what nutrients do and where to get them. But when evaluating your own (or a client’s) specific micronutrient needs, consider these three points…

1. People differ (a lot) in their vitamins and mineral requirements.

Many factors—body size, sex, health conditions and medications, stage of life, activity level, and others—can affect people’s micronutrient needs, as well as how they absorb and use them.

That’s partly why we didn’t include a “recommended daily intake” range for the above nutrients. It just varies too much. Consider the needs of a menstruating Crossfit athlete versus the needs of a sedentary, elderly male on multiple medications.

(If you still want a reference, the FDA has this handy chart. Remember that these are just estimates, and don’t necessarily reflect optimal amounts for all people.)

Generally, though, people have deficiencies for three reasons:⁴

Insufficient intake due to low appetite, restricted diets, illness, or any other situation where certain food groups or calories are reduced or not absorbed properly
Increased need due to illness, injury, surgery, intense physical training (like athletes), or periods of growth (like pregnancy)
Increased loss due to excessive sweating, diarrhea, bleeding, or medical conditions or procedures that lead to a loss of nutrients through urine or other body fluids

If any of these reasons apply to you or your client, be extra wary of deficiencies. Of course, always work with a qualified medical professional when addressing medical issues or clinical deficiencies.

2. Don’t supplement willy-nilly.

If you suspect micronutrient excess or deficiencies in yourself or your clients, get testing to know for sure.

Work with doctors and/or pharmacists when considering supplements, or want to know if your or your clients’ health status or medications interfere with micronutrient absorption and use.

While many supplements are safe, and most people benefit from a good quality multivitamin and mineral supplement, other supplements (see iron, above) may be harmful if taken when they’re not needed.

3. When addressing a potential deficiency, prioritize whole foods.

It’s hard to go wrong with whole foods. (Ever heard of a broccoli overdose?)

Also, most benefits from micronutrients seem to come from a well-balanced diet, rather than supplementation.⁴

As much as possible, choose whole, minimally-processed foods (like the ones we’ve included in our list) when filling nutritional gaps.

You’ll want to include foods like:

colorful fruits and vegetables
mushrooms
herbs and spices
lean proteins such as red meat (particularly organ meats), wild game, poultry, fish, seafood, and eggs
beans and legumes
whole grains
dairy

These foods are the most vitamin- and mineral-rich, but they also contain other nutrients whose benefits we’re only just starting to understand. These other nutrients include:

Phytonutrients, found in plant foods, and can act as antioxidants, lower inflammation, and even influence hormone function
Myconutrients, found in mushrooms and edible fungi, and can help fight bacteria, viruses, and other pathogens
Zoonutrients, found in animal foods, like conjugated linoleic acid (CLA) and creatine, which can help us lower disease risk, build strength and muscle, and preserve brain function

Nutrition science is a relatively young field, and we’re still learning how foods and nutrients affect us.

But that old “apple a day” saying? There’s something to it.

By Ryan Andrews, MS, MA, RD, RYT, CSCS

References

Click here to view the information sources referenced in this article.