Supplementation has become increasingly popular in the United States over the past 20 years. Many products have potential application and benefits to target populations, but it is rare that a supplement truly enhances the health or performance of the general population better than an optimized diet. That said, there is always a place for supplementation, especially as a way to fill the gaps in the diet. Endurance athletes need to pay attention to a couple key nutrients during training. If these cannot be consumed adequately through diet, supplementation should be considered to prevent deficiency and keep the body functioning at its best.
Calcium: Dairy Products, Kale, Collards, Black Eyed Peas, Fatty Fish, Bone Marrow
Magnesium: Dark Leafy Greens, Nuts, Seeds, Fish, Beans, Lentils, Grains
Iron: Meats, Animal Products, Seeds, Nuts, Beans, Whole grains
B12: Meats and Animal Products
B6: Meat, Starchy Vegetables
Vitamin C: Citrus fruits, Peppers, Dark Greens, most Fruit
The vitamins and minerals listed above either have an increased need in endurance athletes, or tend to be under consumed by many runners. Using the sources listed, assess your intake of these nutrients on a daily basis. Ideally you are getting at least 3 servings of each of these items daily. If your consumption is below that amount, these items may be compromising your nutrition status and performance.
Vitamin C is the only micronutrient aside from the electrolytes that we know runners need more of. Estimates range between 200 and 500mg per day based on intensity and duration of activity. Supplementation is generally unnecessary for runners who use fruit as a carbohydrate source before, during and after activity. For those who choose to supplement, the body does not absorb much more than 100mg at a time, so the large doses of vitamin C are often wasted. Instead of buying 1000mg, try using 100mg doses spread throughout the day to maximize absorption.
All the other nutrients tend to be under consumed based on dietary restriction. Calcium is often hard to consume enough of without dairy, and magnesium is often lacking in those following energy-restricted diets. In both instances, attention to the food sources can ensure adequate intake with little effort. If dairy is not a food group in your diet, and you do not consume the other sources consistently, I usually recommend using almond or coconut milk twice daily. For those who prefer supplementation, calcium citrate is the best option for absorption. It can be taken in 600mg doses, or in smaller doses spread throughout the day.
Vegetarians commonly under consume iron, B12 and B6. Most of the time, supplementation becomes the most sustainable way to encourage adequate intake of these nutrients. Even omnivorous females often struggle to consume adequate iron daily. Women need significantly more iron than men. Unless the diet contains consistent red meat intake, or an individual uses a cast iron skillet, it is very likely a female runner will show signs of iron deficiency and even iron deficiency anemia without supplementation.
Overall supplementation is unnecessary in the general population assuming the diet is adequate. As a runner, it is important to look for gaps in your diet to assess your need for certain vitamins and minerals. Once you have identified areas of concern, try to integrate food sources into your day. If you find it hard to consistently consume enough of a certain nutrient, then supplementation may be a more sustainable option for you. Use diet to drive your success, and allow supplements to fill the gaps that exist!
Andrew Wade, RDN, LDN