Vitamins and minerals are affected by increased physiologic demands and the stress of exercise. Female athletes may be at particular risk for certain deficiencies. Read more below.
Inadequate Energy Consumption
Simply stated, many nutrient deficiencies occur as a result of not consuming adequate calories to meet the body’s demand. Often with inadequate calories, nutrient intake is sub-optimal. Research has shown that female athletes and those in weight-specific sports (such as gymnasts, boxers, runners, dancers, etc.) are more at risk. Female athletes are also more at risk for disordered eating patterns and what is known as “The Female Athlete Triad”.
The 2014 Female Athlete Triad Coalition Consensus Statement defines it as a medical condition that contains the following;
- low energy availability with or without disordered eating
- menstrual dysfunction
- low bone mineral density
It was also found that protein in this population is below the RDA (Recommended Dietary Allowance). Protein needs depend on the sport (athletes should work with a registered dietitian specializing in sports nutrition for personalized needs), and can range from 1.2-1.7 g/kg/day.
Over 50% of athletes are iron deficient. This is due to menstruation, inadequate nutrient intake, GI bleeding, hemolysis (especially in endurance athletes), sweat loss and malabsorption of iron.
Deficiencies in iron can affect athletic performance as well as immune function and overall cognitive abilities.
A comprehensive blood panel can be one of the best ways to identify an iron deficiency, especially if fatigue is a major complaint for the athlete.
Factors that enhance absorption of Iron include;
- Consumption of heme iron (primarily found in meat, poultry or fish)
- Consuming iron rich foods with sources of vitamin C (bell peppers, citrus, broccoli, kiwi, strawberries, etc.)
- Low iron stores
- Normal gastric acid secretion
- High demand for red blood cells (with increased exercise or hemolysis)
Factors that inhibit absorption of Iron include;
- phytates (phytic acid) and oxalates
- tannins in tea and coffee
- adequate iron stores (indicating that more is not needed)
- excessive intakes of other minerals
- reduced gastric acid production
Vitamin K is also a lesser-known vitamin, especially important for women due to it’s role in estrogen and bone formation.
- Vitamin K is lower in our diets than previously thought due to diets high in sugar and processed foods, higher intakes of Vitamin A nd Vitamin E (above upper limits) and antibiotics disrupting intestinal barrier function and decreased production/metabolism of vitamin K-1 and K-2.
- Vitamin K-1 (found in plants), K2 (produced by gut bacteria), and K3 (synthetic form)
- Average diet contains about 75-150 mcg/day, although 300-750 mcg/day may be optimal
- Food sources include;
- leafy green vegetables (spinach, turnip greens)
- green tea
Exercise does not seem to increase needs on it’s own, so ensuring adequate intake from a diverse diet is important.
Calcium & Vitamin D
Both calcium and vitamin D, along with other nutrients such as phosphorus and vitamin K (discussed below) are important for bone health and approximately 1/3 of female athletes are deficient.
To assess calcium and vitamin D, it is important to look at blood work, review dietary intake, lifestyle factors (sun exposure, exercise, sleep, etc.) and prevalence of stress fractures and illness.
- Exercising in heat can increase needs
- Calcium is controlled by parathyroid hormone (PTH), vitamin D and calcitonin
- Good food sources include
- High quality dairy and non-dairy beverages fortified with calcium
- organic tofu
- kale and other dark green leafy vegetables
- canned salmon (with the bones)
- Risks of deficiency include;
- Autoimmune disease and other chronic diseases
- Muscle weakness
- Good food sources include;
- Fatty, cold water fish such as salmon
- Organic organ meats (especially liver)
- You also get vitamin D from sun exposure (it is recommended to get ~10-15 minutes of sun/day at peak hours (between 10am-2pm)
- Vitamin D3 supplementation
The primary vitamins and minerals discussed above are of particular concern to female athletes, however, it is important to consume a healthy, diverse diet full of colorful fruits and vegetables to ensure adequate intake.
- Prebiotics: asparagus, artichokes, garlic, onions, banana (on the greener side), apples, flax seed, jicama
- Probiotics: fermented vegetables, sauerkraut, kimchi, kefir, yogurt with live & active cultures
It is always preferred to obtain nutrients from foods, but if an athlete is not able to consume amounts necessary for health and optimal performance, supplementation may be recommended.
Other nutrients that may be especially important to support those at higher activity levels include Magnesium, Zinc, and B Vitamins.
Hueglin S. Nutrition and the Female Athlete. Olympic Coach. 2014;25(4):29-32. Accessed September 30, 2020.
Karpinski, C., & Rosenbloom, C. (2017). Sports nutrition: A handbook for professionals: Sports, cardiovascular, and wellness nutrition dietetics practice group. Chicago: Academy of Nutrition and Dietetics.
Mountjoy M, Sundgot-Borgen J, Burke L, et al. International Olympic Committee (IOC) Consensus Statement on Relative Energy Deficiency in Sport (RED-S): 2018 Update. International Journal of Sport Nutrition & Exercise Metabolism. 2018;28(4):316-331. Accessed September 30, 2020.