Vitamin and mineral supplements are readily available and easy to take. Walk through any grocery store and there is surely an aisle stocked with hundreds of different vitamin and mineral supplements claiming optimal health. Taking a vitamin or mineral supplement may seem like an easy way to potentially boost performance with no risk. It may also feel like an easy back-up plan just in case your diet is lacking in certain nutrients. Do athletes need to take a vitamin or mineral supplement? This is a very common question, and there is a lot of exciting research on this topic. Exercise stresses many of the metabolic pathways that require vitamins and minerals. Because of the high demands of training, athletes have a higher need for some vitamins and minerals. However, if your diet provides enough calories (AKA you’re eating enough food) and you eat a wide variety of foods, you are probably getting enough vitamins and minerals and don’t need an additional supplement. Taking a vitamin and mineral supplement does NOT improve performance, unless it is reversing a pre-existing nutrient deficiency. However, there are some vitamins and minerals of special concern for athletes, which are highlighted below:
The role of iron is to help the body use and carry oxygen to muscles. Iron deficiency can lead to anemia and negatively impacts mental, physical and athletic performance. Iron in food is classified as either heme iron or non-heme iron. Heme iron comes from animal sources such as meat, fish and poultry and is readily absorbed. Non-heme iron comes from plant sources such as cooked spinach or lentils. Non-heme iron is not as readily absorbed, but pairing with foods high in vitamin C enhances the absorption. Check out my sweet-potato & beet hummus recipe. It includes chickpeas, a good source of non-heme iron, and sweet potatoes, a good source of vitamin C, to enhance the absorption. I really encourage athletes (especially women) to get their iron checked periodically. The iron requirements for female athletes may be increased by up to 70% and there is a very high incidence of iron depletion among athletes. However, it is NOT a good idea to take iron supplements without first having your blood checked to determine if you are deficient and would, therefore, benefit from supplementation. Iron supplements can be toxic.
Side note: If you have had your blood checked and a health professional has recommended that you take an iron supplement, it should NOT be taken immediately after exercise since absorption of iron is impaired during this time.
The B-vitamins include: thiamin, riboflavin, niacin, vitamin B6, pantothenic acid, biotin, folate and vitamin B12. The B-vitamins have a wide variety of roles, including releasing energy, building and repairing tissue and healthy red blood cell development. While athletes probably need higher amounts of B-vitamins, they are found in a wide variety of foods. The increased requirements for the B-vitamins can generally be met through diet with higher energy intakes. Again, this means that if you’re eating enough food and a wide variety of foods, then you’re probably consuming enough of the B-vitamins. However, vitamin B12 is only found in foods of animal origin like meat, eggs or milk products. If you don’t eat animal products, then it’s important to include foods, like a soy beverage, that have been fortified with vitamin B12.
Antioxidants include beta-carotene, vitamin E, vitamin C and selenium. They help protect the body’s cells from oxidative damage. The current literature does not support antioxidant supplementation as a means to prevent exercise induced oxidative stress. Athletes should NOT take antioxidant supplements because they may actually be harmful and may, in fact, negatively influence training adaptation. You can obtain antioxidants by consuming nutrient-rich foods like vegetables, fruits, nuts, whole grains and legumes.
Vitamin D and Calcium:
Vitamin D and calcium are important for more than just healthy bones and teeth. They also impact muscles, nerves and hormone function. Vitamin D is also important for a healthy immune system. There is so much exciting new research on vitamin D supplementation in athletes that I could probably write a whole blog on this topic! At this time, current data does not support vitamin D supplementation as a way to improve performance. However, vitamin D is not found naturally in many commonly consumed foods. Only egg yolk and some fatty fish naturally contain vitamin D. In Canada, cows’ milk and some other food products are fortified with vitamin D. Health Canada recommends consuming 2 cups of milk a day to meet the vitamin D requirements. Vitamin D can also be made when sun hits the bare skin. Unfortunately, during the late fall and winter in Canada, we cannot make enough vitamin D from the sun. Since athletes tend to consume little vitamin D from diet and dietary interventions alone have not been shown to be a reliable means to resolve poor vitamin D status, supplementation or sun exposure may be required to maintain sufficient vitamin D status. Athletes that live at northern latitudes or primarily train indoors may benefit from vitamin D supplementation. Vitamin D is also important for calcium absorption. Calcium is found in milk products and also some dark green vegetables. The need for calcium supplementation should be determined after a thorough assessment of usual dietary intake.
In summary, while athletes do have an increased requirement for vitamins and minerals, these increased requirements can usually be met through consuming a diet that provides enough calories and includes a variety of different foods. Athletes who frequently restrict their food intake, rely on extreme weight-loss practices, eliminate food groups or consume poorly chosen diets may require a vitamin or mineral supplement. However, a trained professional should carefully analyze your diet and your blood should be checked before taking a vitamin or mineral supplement. Remember- more isn’t always better!