Vitamin D is often referred to as the sun vitamin because the main source of the vitamin is obtained from sun exposure. However, many people are vitamin D deficient.
Vitamin D is a fat-soluble hormone that plays a vital role in bone health, muscle function, adaptive immunity, and many human diseases such as cancer, diabetes, and musculoskeletal health
Vitamin D deficiency
Indeed, vitamin D deficiency is a global public health problem.
Globally, around 1 billion people are vitamin D deficient, while over 77% of the total population is insufficient.1 What does it mean if you are an athlete who plays indoor sports, trains indoors year-round and rarely outdoors is the day going?
What if you also live in the northern hemisphere? You are probably not getting enough vitamin D. Inadequate sun exposure can dramatically increase your risk of vitamin D deficiency. It can lead to a wide variety of negative health effects and affect athletic performance.
Research has shown that vitamin D significantly affects muscle weakness, pain, balance, and fractures in the aging population.1
Vitamin D plays a key role in: 1
Vitamin D deficiency occurs when the blood level falls below 20 ng / ml (.
Research has shown that 40-50 ng / ml (100-125 nmol / l) seems ideal for optimizing athletic performance.1
Who is at high risk?
People at high risk of vitamin D deficiency: 1.5
- Decreased food intake: certain malabsorption syndromes such as celiac disease, short bowel syndrome, gastric bypass, inflammatory bowel disease
- Decreased exposure to sunlight. About 50% to 90% of vitamin D is absorbed through the skin. 20 minutes of sunshine daily, with 40% of the skin exposed, is required to prevent deficiency.
- Aging Adults: The ability to synthesize vitamin D decreases by up to 75% with age.
- Overweight and obese people: Carrying excess body fat can increase their risk by up to 55% because vitamin D is trapped in adipose tissue and not available in the bloodstream.
See the previous blog about factors that affect vitamin D levels.
Athletes who practice indoor sports
Athletes who play indoor sports are at a higher risk of vitamin D deficiency.
Hockey players specifically spend a large amount of their time training, conditioning, and competing indoors. This makes it difficult to get vitamin D from sun exposure. Another study found that 88% of the population were receiving less than the optimal amount of vitamin D.3
Several studies link vitamin D status to bone health and general bone injury prevention in the sports population.
Research and Vitamin D Deficiency
Studies have shown that inadequate vitamin D levels are linked to a higher risk of stress fractures in young men and women published in the Journal of Foot & Ankle Surgery. 4
In a study published in the journal, Nutrients rated the vitamin D status of college basketball players during the season. Players were assigned either a high dose, a low dose, or no vitamin D at the start of the study, depending on their circulating 25-hydroxyvitamin D levels, to determine the optimal status of the optimal dosage of vitamin D3 supplementation.
The results showed that 13 of the 20 participants did not have enough vitamin D at the start of the study. Another finding was that of the examined athletes and The darker skin pigmentation increased the risk of vitamin D insufficiency at the start of the study.
The researchers found that most athletes who were inadequate in vitamin D benefited from a supplement of 10,000 IU to improve their status
Another study concluded that black professional footballers have higher levels of vitamin D deficiency than white ones
The study also suggests that vitamin D deficient professional soccer players may also be at higher risk of fractures
Increasing performance is the desire of every athlete as it can lead to improved performance on the field. Your muscle tissue has several important receptor sites for vitamin D and supports the generation of electricity.1
A study of soccer players found that increasing baseline vitamin D status over a period of 8 weeks led to increased vertical jumps and sprint times of 10 meters.9
Of course, we need more research in this area to identify the relationship between vitamin D levels and performance.
Nonetheless, the current literature is promising and that at least baseline vitamin D values should be desirable.
Sources of Vitamin D.
The best sources of vitamin D are egg yolks, mushrooms, fortified milk, yogurt, cheese, salmon, and mackerel.8th
Food sources rich in vitamin D:
- 6 ounces. fortified yogurt = 80 IU
- 3 ounces of salmon = 794 IU
- 1 cup fortified cereal = 40 IU
- 1 cup of fortified milk = 120 IU
- 1 egg yolk = 41 IU
- 1 cup of fortified orange juice = 137 IU
Athletes who exercise indoors, consume little vitamin D-rich sources, and live> 35 degrees north or south can benefit from a vitamin supplement of 1,500 to 2,000 IU per day to keep vitamin D concentrations in a sufficient range.
Athletes who have a history of stress fractures, common illnesses, pain or weakness, or signs of overtraining should be assessed for vitamin D status.
Vitamin D is best absorbed with a high-fat meal.
It is important to see a doctor to further determine vitamin D levels and to meet with a registered dietitian to further discuss nutritional intervention.
1. Ogan, D. & Pritchett, K. “Vitamin D and the Athlete: Risks, Recommendations, and Benefits.” Nutrients, 5 (6), 1856-1868. 2013.
2. Umar, M., Sastry, KS & Chouchane, AI, “Role of Vitamin D Beyond Skeletal Function: An Overview of Molecular and Clinical Studies.” International Journal of Molecular Sciences, 2018, 19 (6), 1618.
3. Bendik, I., Friedel, A., Roos, FF, Weber, P. and Eggersdorfer, M. “Vitamin D: a critical and essential micronutrient for human health.” Frontiers in Physiology, 5, 248, 2014.
4. Elsevier Health Sciences. (2015, December 14th). “Low vitamin D levels can increase the risk of stress fractures in active individuals: Experts recommend active individuals who participate in higher-impact activities may maintain higher levels of vitamin D.” ScienceDaily. Retrieved October 19, 2020.
5. Sizar O., Khare S., Goyal A. et al. “Deficiency of Vitamin D.” [Updated 2020 Jul 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-.
6. Sekel, NM; Gallo, S .; Fields, J .; Jagim, AR; Wagner, T .; Jones, MT “The Effects of Cholecalciferol Supplementation on Vitamin D Status in a Diverse Population of College Basketball Athletes: A Quasi-Experimental Study.” Nutrients, 2020, 12, 370.
7. National Health Institutes – Food Supplements Office – “Vitamin D – Information Sheet for Health Professionals”. [accessed October 19, 2020].
8. Maroon JC, Mathyssek CM, Bost JW, Amos A., Winkelman R., Yates AP, Duca MA, Norwig JA. “Vitamin D Profile in National Football League Players.” Am J Sports Med. 2015, May; 43 (5): 1241-5. Epub 2015, February 3rd. PMID: 25649084.
9. Close, GL, Russell, J., Cobley, JN, Owens, DJ, Wilson, G., Gregson, W., Fraser, WD & Morton, JP, “Assessment of Vitamin D Concentration in Non-Supplemented Professional Athletes and Healthy Adults during the winter months in the UK: effects on skeletal muscle function. “Journal of Sports Sciences, 31 (4), 344–353. 2013.