Micronutrients: Small Doses, Big Effects
Nutrition Foundation Pillar
There’s a lot of talk about calories and macronutrients, but much less about micronutrients. Yet these vitamins and minerals, which are needed in tiny amounts, are essential for nearly all of your body’s functions—and a deficiency can have serious consequences.
Vitamins and Minerals: A Brief Overview
Vitamins are divided into fat-soluble (A, D, E, K) and water-soluble (B vitamins and vitamin C). Minerals include five major minerals (calcium, phosphorus, potassium, sodium, magnesium) and several trace minerals (iron, zinc, copper, iodine, selenium, etc.). With very few exceptions, the body cannot produce them; they must be obtained from food.
What They Do
Despite their small quantities, they play a role in hundreds of processes: energy production, protein metabolism, bone health, oxygen transport, immune function, and tissue repair. Several of them (vitamins A, C, and E) also act as antioxidants, limiting cellular damage.
Delight Them with a Meal
For most people, five servings of fruits and vegetables a day, as part of a varied diet, provide the essentials. However, certain micronutrients are more readily found in animal products (zinc, iron, vitamin B12, vitamin A), and iron and zinc from plant sources are less readily absorbed due to compounds found in whole grains and legumes.
Deficiencies: Who Is at Risk?
Any diet that excludes an entire food group increases the risk of nutritional deficiencies. Vegan and vegetarian diets increase the risk of iron, zinc, and vitamin B12 deficiencies; so do very low-calorie diets followed without professional guidance. The most common deficiencies involve iron, vitamin D, iodine, folate, zinc, and vitamin B12—which is why it’s important to consult a professional before starting a restrictive diet.
Supplements: Rarely the Solution
Here’s what the industry doesn’t tell you: for a healthy person who eats a varied diet and has no proven deficiencies, supplementation offers no benefits. Worse, at high doses, certain supplements can be harmful—high doses of vitamin E have been linked to increased mortality, and vitamin A to an increased risk of lung cancer. The actual benefit is limited to people who are truly deficient.
For those who exercise, the message is more nuanced: a deficiency (in iron, magnesium, zinc, or vitamin D) can indeed negatively affect VO₂max, recovery, and strength. The right approach is not to take supplements for everything “just in case,” but to identify and correct any actual deficiencies.
It all starts with a balanced meal—check out our overview of the macronutrients.
References
Shenkin, A. “Micronutrients in Health and Disease.” Postgrad Med J. 2006;82(971):559–567.
Beck KL, von Hurst PR, O'Brien WJ, Badenhorst CE. “Micronutrients and athletic performance: A review.” Food Chem Toxicol. 2021;158:112618.
Kiani AK et al. “Major Nutritional Deficiencies.” J Prev Med Hyg. 2022;63(2 Suppl 3):E93-E101.
Bailey RL, West KP Jr, Black RE. “The Epidemiology of Global Micronutrient Deficiencies.” Ann Nutr Metab. 2015;66(Suppl 2):22-33.
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This article is provided for educational purposes only and does not constitute medical advice. If you have any health conditions, consult a doctor before starting to exercise.
