Micronutrients for Athletes: Vitamins and Minerals That Support Training

Why Micronutrients Matter for Active Adults

Vitamins and minerals do not fuel a workout directly the way carbohydrate does, but they enable the processes that do. Micronutrients are required for metabolic processes relevant to exercise, including energy production, oxygen delivery and transfer, tissue repair, and growth and development. Vitamins are organic compounds needed in small amounts that the human body is generally unable to synthesise, so they must come from dietary intake. Minerals are inorganic substances, classified by daily physiological requirement into macrominerals such as sodium, potassium, calcium, phosphorus and magnesium, and trace elements such as iron, zinc, copper, chromium and selenium.

Training changes the picture in two ways. Physical activity increases the utilisation of micronutrients through increased energy metabolism, increased demand from exercising tissue, and losses from sweat, urine and faeces. At the same time, athletes in sports with high energy requirements are likely to have increased micronutrient requirements, yet there is insufficient data to quantify the specific increased levels required. In practice this means the goal is adequacy, not megadosing.

• Micronutrients support muscle contraction, oxygen transport, and the metabolism of carbohydrate, protein and fat.
• Regularly occurring circumstances that can raise requirements include high sweat and urine losses of electrolytes and zinc, low energy intakes affecting iron, and vegetarian or vegan eating patterns affecting haem iron.
• Vitamin D concentrations may be low in athletes who train and compete in winter sports or predominantly indoors.
• Iron stores may be more compromised in athletes undertaking high-intensity and endurance-based exercise.
• No single micronutrient is more important than the others for athletic performance.

Sources: Food and Chemical Toxicology (Elsevier), Sports (MDPI), via PubMed Central, Frontiers in Sports and Active Living

Key Vitamins: Roles and Food Sources

The B vitamins, vitamin C, vitamin E, vitamin A and vitamin D all appear in the sports nutrition literature, but their roles differ. B vitamins are involved in energy metabolism and tissue repair, which is consistent with their general function in converting food into usable energy. Vitamin C, vitamin E, beta-carotene and selenium are antioxidant micronutrients that help counter oxidative stress associated with regular intense exercise. Vitamin A exists mainly in two forms: animal-source retinol and plant-based provitamin A carotenoids, and intake of beef liver, eggs, dairy, seafood and dark leafy green vegetables may help meet dietary requirements.

Vitamin D deserves separate attention because of how it is obtained. Unlike most vitamins, it can be made in the skin from sunlight, so low concentrations are more likely when training happens indoors or in winter. For the rest of the vitamins, a balanced diet that includes lean protein sources, whole grains, fruits and vegetables is generally sufficient for normal bodily functions.

• B vitamins: involved in energy metabolism and tissue repair; found across whole grains, meat, fish, eggs, dairy and legumes.
• Vitamin A: retinol from liver, eggs, dairy and seafood; provitamin A carotenoids from dark leafy greens and orange vegetables.
• Vitamin C and vitamin E: antioxidant roles relevant to oxidative stress from regular intense exercise; found in citrus, peppers, berries, vegetable oils, nuts and seeds.
• Vitamin D: status is influenced by sun exposure, so indoor and winter athletes are more likely to run low.

Sources: Sports (MDPI), via PubMed Central, Cathe Friedrich (cathe.com)

Key Minerals: Roles and Food Sources

Minerals are involved throughout the systems that training depends on. Calcium plays a role in skeletal muscle contraction and can be found in milk, yogurt, cheese, dark leafy greens, tofu, nuts, fish and fortified cereals. Magnesium contributes to energy metabolism and supports typical muscular contraction and relaxation, and physically active people might need more magnesium than inactive people to sustain peak exercise performance, although most studies reviewed reported little impact of high-dose magnesium on exercise performance. Iron, copper, vitamin B6, vitamin B12 and folate are required for red blood cell formation and oxygen transport to muscle cells, which is why iron gets so much attention in endurance sports.

Iron deserves a specific note because of the pattern in the evidence. Iron stores may be more compromised in athletes undertaking high-intensity and endurance-based exercise, and the combination of low energy intake and training load is a recognised risk pattern. Endurance athletes such as runners, cyclists and triathletes may be most at risk for micronutrient deficiency because of low energy consumption, longer physical activity duration and increased sweat rate. Food sources of iron include red meat, poultry, fish, shellfish, eggs, legumes, tofu, spinach and fortified grains; plant sources are absorbed less efficiently, which is why vegetarian and vegan patterns are flagged as a circumstance that can increase requirements.

Sources: Sports (MDPI), via PubMed Central, National Strength and Conditioning Association (NSCA), Cathe Friedrich (cathe.com)

Eating for Micronutrient Adequacy

The central message from the research is reassuring: a well-balanced diet in a healthy individual is generally adequate to obtain all micronutrients in recommended doses for normal bodily functions. The open question is whether standard recommendations are adequate for athletes, and researchers and clinicians continue to discuss this.

For active adults, that translates into a few practical habits rather than a complicated system. Build meals around a mix of lean protein, whole grains, fruits and vegetables, and rotate the foods within each group so you are not relying on a narrow set of items. Pay attention to energy intake, because low energy availability is one of the main pathways to a shortfall. And give special thought to the circumstances that raise requirements: heavy sweating, plant-based diets, indoor or winter training, and high-intensity endurance blocks.

Meal prep helps here for a simple reason: it makes variety easier to sustain. A weekly plan that includes several different protein sources, two or three colours of vegetables, and a whole grain or starchy vegetable at most meals will cover more micronutrient ground than any single food repeated every day.

• Aim for variety across the week, not perfection at every meal.
• Include a protein source at most meals, alternating between animal and plant options if you eat both.
• Add at least one fruit or vegetable to each meal, and rotate what you choose.
• Watch total energy intake during heavy training blocks; undereating is a common route to micronutrient shortfalls.
• If you eat vegetarian or vegan, plan iron, zinc, B12 and omega-3 sources deliberately rather than by default.

Sources: Food and Chemical Toxicology (Elsevier), Sports (MDPI), via PubMed Central, Frontiers in Sports and Active Living

Reading Labels Without Overbuying

Athletes commonly use vitamin or mineral supplements, with a meta-analysis finding approximately 50% of athletes were using them, and around 80% of collegiate athletes have been reported to use supplements, with multivitamin and multimineral products among the most common. Use is not the same as need, and the balance of the recent literature suggests that micronutrient supplementation in well-nourished athletes does not enhance physical performance.

That does not make every supplement pointless, but it does mean the decision should be driven by a reason rather than by habit or marketing. Before adding a product, ask what gap it is filling. If you already eat a varied diet and have no diagnosed deficiency, a multivitamin is unlikely to improve your training. A more useful approach is to look at your plate first: if you consistently miss a food group, address that before buying a pill that partially replaces it.

• Check whether the product is a multivitamin, a single-nutrient supplement, or a blend, and what each provides.
• Be cautious of products marketed specifically for performance without a clear nutritional rationale.
• Remember that excessive intake of dietary supplements may impair the body's physiological responses to exercise that support adaptation to training stress.
• Avoid taking supplements without confirming a deficiency, and treat any supplement decision as one to discuss with a qualified professional.

Sources: Food and Chemical Toxicology (Elsevier), Sports (MDPI), via PubMed Central, Frontiers in Sports and Active Living

When to Talk With a Professional About Supplementation

There are situations where supplementation may be appropriate. Micronutrient supplementation may be warranted in cases such as a diagnosed deficiency, compromised energy intake, or training and competing at altitude, and these micronutrients should be prescribed by a medical professional. The same principle appears in the systematic review evidence: athletes should only take micronutrient supplements with the consultation of a specialised physician or nutritionist, and should avoid taking them without confirming a deficiency.

A practical way to open that conversation is to bring your training load, your typical weekly food pattern and any symptoms you have noticed. Ask directly whether your intake looks adequate, whether any specific nutrient is worth testing, and whether your situation qualifies as one where supplementation is justified. Those are reasonable questions for a clinician or registered dietitian, and they keep the decision grounded in your actual circumstances rather than a general claim about athletes.

• A diagnosed deficiency is the clearest reason to supplement, and the dose should come from a medical professional.
• Consistently low energy intake alongside heavy training is a recognised risk pattern worth raising with a professional.
• Altitude training and indoor or winter training blocks are circumstances where specific nutrients may need attention.
• Bring your food pattern and training schedule to the appointment so the advice fits your real routine.

Sources: Food and Chemical Toxicology (Elsevier), Sports (MDPI), via PubMed Central, Frontiers in Sports and Active Living