Micronutrients that matter
Micronutrients that matter. The small stuff, the unsexy part of your diet that you rarely take note of.
But how much do you really need to know and does it really matter?
Do you train?
Are you a lady?
Are you a veggie?
If it’s a yes to one of those then keep reading.
What are micronutrients anyway?
Micronutrients are the vitamins and minerals we require in small amounts to keep our bodies functioning properly. These range from things like energy, bone health, immunity, recovery and injury. In most cases, providing you’re eating a well-balanced diet then additional supplementation should not be required and will not lead to an improvement in performance or health.
There are some exceptions where precautions should be taken to ensure adequate micronutrient availability. Athletes who restrict energy intake, are vegetarian, remove whole food groups or undertake sever weight loss strategies can put themselves at risk with an inadequate amount of vitamins and minerals (5, 10). Also, due to the heavy demands of competitive fitness, there may be a need for additional micronutrients to help with performance, repair and maintenance in sports like this. (1)
So which ones?
This is not an exhaustive list but the three you need to be aware of are iron, vitamin D and calcium.
Iron
Iron is required by the body for haemoglobin and myoglobin that are responsible for transporting oxygen from the lungs to the muscle. Obviously, with a sport like competitive fitness then oxygen carrying capacity is pretty important, not just for endurance but also cognitive function and immunity (3). Inadequate iron or deficiency can impair and limit work capacity and impair muscle function, intense training, health and cognitive performance (10, 11). Deficiency is more obvious for those participating in intense and endurance activities, vegetarians and when hemolysis could occur (the damage of red blood cells caused by repetitive prolonged damage, in sports like competitive fitness!). Women tend to be at a greater danger then men to deficiency from menstrual blood loss and an increased likelihood of restricted eating (2).
These types of populations should aim for an intake greater than the recommended NHS guidelines RDA (14.8 mg for women and >8 mg for men) by following a couple of simple guidelines:
Eat foods rich in heme iron at least 4 times a week (e.g. liver or red meat).
Include non-heme iron food sources (e.g., dried fruit, legumes, and green leafy vegetables).
Combine non heme-iron foods with meat or vitamin C-rich food (orange juice) to increase iron absorption.
Avoid drinking tea at meals
Avoid supplementation post exercise as absorption is interfered with.(Human-kinetics, 2017)
Vitamin D
Synthesized by sunlight, vitamin D helps calcium absorption and is key for maintaining good bone health (8). A recent surge in research has also highlighted the correlation with vitamin D and injury prevention, muscular function, muscle growth, reduced inflammation and decreased risk of illness (6).
Who needs it? Us English! Well, anyone who lives at latitudes >35th parallel. If you have a darker complexion or avoid the sun you might also be at a higher risk of a deficiency (7).
Recent research suggests that the current DRI of 10 μg/d (400 IU/d) (9) maybe difficult to reach without supplementation. There’s currently not enough empirical evident supporting vitamin D3 as an ergogenic aid however if you live in the cold, rarely see sunshine then supplementation is worthwhile.
Calcium
Responsible for growth, muscle contractions and bone repair, it is important athletes get enough calcium in their diets. A deficiency can lead to decreased bone density and an increased likelihood of stress fractures and osteoporosis. Issues arise from low energy availability (not eating enough/excessive exercise), eating disorders and avoidance of dairy or calcium rich foods (6). So again, providing you’re eating a balanced diet comprising of dairy, fish (with bones!) and dark least veg then you should comfortably attain the RDA of 1000mg per day and supplementation should not be necessary.
To sum up
Providing you’re eating a well-balanced nutrient rich diet, additional supplementation should not be necessary. However, due to the heavy demands of competitive fitness, it may sometimes be warranted. My advice would be to get tested for Vit D and iron and make an informed decision based on these results. Look out for common symptoms associated with a deficiency (are you getting injured a lot, struggle to recover and consistently lack energy?) but in the meantime, make a concerted effort to eat the rainbow (cheesy but true!) include iron and calcium rich foods on a weekly basis and get some sunshine J Remember, a healthy athlete is a better athlete.
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References
Driskell, J. and Wolinsky, I. (2006). Sports nutrition. 1st ed. Boca Raton: CRC/Taylor & Francis.
Gabel, K. (2006). Special Nutritional Concerns for the Female Athlete. Current Sports Medicine Reports, 5(4), pp.187-191.
Gleeson, M. (2005). Assessing immune function changes in exercise and diet intervention studies. Current Opinion in Clinical Nutrition and Metabolic Care, 8(5), pp.511-515.
human-kinetics. (2017). Recommendations for micronutrient intake in athletes. [online] Available at: http://www.humankinetics.com/excerpts/excerpts/recommendations-for-micronutrient-intake--in-athletes [Accessed 19 Mar. 2017].
Medscape. (2017). Nutrition and Athletic Performance. [online] Available at: http://www.medscape.com/viewarticle/717046_8 [Accessed 18 Mar. 2017].
Nutrition and Athletic Performance. (2015). Medicine & Science in Sports & Exercise® and in the Journal of the Academy of Nutrition and Dietetics, and the Canadian Journal of Dietetic Practice and Research., (Position Stand).
Ogan, D. and Pritchett, K. (2013). Vitamin D and the Athlete: Risks, Recommendations, and Benefits. Nutrients, 5(6), pp.1856-1868.
Pojednic, R. and Ceglia, L. (2014). The Emerging Biomolecular Role of Vitamin D in Skeletal Muscle. Exercise and Sport Sciences Reviews, 42(2), pp.76-81.
Vitamin D and Health. (2016). Scientific advisory Committee on Nutrition.
Whiting, S. and Barabash, W. (2006). Dietary Reference Intakes for the micronutrients: considerations for physical activity. Applied Physiology, Nutrition, and Metabolism, 31(1), pp.80-85.
Woolf, K. and Manore, M. (2006). B-Vitamins and Exercise: Does Exercise Alter Requirements?. International Journal of Sport Nutrition and Exercise Metabolism, 16(5), pp.453-484.