There appears to be a lack of consensus between the different international bodies (the Institute of Medicine and the Endocrine Society guidelines) on what the level of Vitamin D deemed as deficient is; the IOM says less than 12 ngs/mL of serum 25 hydroxy-vitamin D, whereas the Endocrine society says less than 20 ngs/mL of 25(OH)D. Sufficient amounts by Institute of Medicine guidelines are 20 ng/mL, compared to 30 – 60 ng/mL by the Endocrine society. This then has an effect on some of the literature and research, as the statistics in one country can be interpreted differently if you are referring to a different set of guidelines.
Vitamin D deficiency will be treated with oral supplementation of 50,000 International Units of Vitamin D3 a week for 8 weeks, or 6,000 International Units daily to achieve a blood level of 25(OH)D above 30 ng/mL, followed by maintenance therapy of 1,500 – 2000 International Units /day. Remember to get regular repeat blood tests, at least every 3 months, to check if your levels have increased. You can also increase your intake of oily fish, mushrooms, eggs and vitamin D fortified products.
Get some sun exposure every day if possible. The sun shining on your skin triggers an inactive form of Vitamin D to be metabolized by the liver and kidneys to produce an active form of vitamin D, which goes on to help strengthen your bones and keep you healthy. Aim to get about 10 – 15 minutes of UVB on your hands and face daily. UVB rays do not pass through glass, so sitting in the sun directly is the best. In very hot countries or in the peak of summer this may be too much exposure, as you don’t want to burn as this then increases your risk of skin cancer. You can check the UV index in your country with phone apps, they will guide you into how much sun exposure is required day to day depending on the countries weather and by your skin colour. A good guide for some hotter or cooler countries as the sun exposure times may vary a lot.
Vitamin D is important for bone health and it helps regulate calcium metabolism. Adequate Vitamin D will help absorb calcium. Calcium-rich food sources include dairy products, dark green leafy vegetables, legumes, nuts and fortified foods. The RDI (recommended daily intake) for calcium is 1000 milligrams/day for healthy adults (slightly higher requirements of 1,300 milligrams /day for pregnant women or lactating mothers and post-menopausal women). Think dairy daily!
Regular daily exercise helps to strengthen your bones – this effect will be enhanced by good Vitamin D status from healthy amounts of sun exposure and a good dietary intake of Vitamin D rich foods. There is some emerging research on Vitamin D and exercise performance, and one of our presentations released this month by Dr. Kirsty Fairbairn discusses Vitamin D – the latest ergogenic aid. Does consuming vitamin D help with sprint performance in rugby players or not? Check out her latest presentation to find out! So make sure you get out into the lovely sunshine (but not too much!), exercise daily to strengthen your bones, and try to have some Vitamin D (and calcium) rich foods daily.
So make sure you get out into the lovely sunshine (but not too much!), exercise daily to strengthen your bones, and try to have some Vitamin D (and calcium) rich foods daily.
Further reading:
Ross, A. C., Manson, J. E., Abrams, S. A., Aloia, J. F., Brannon, P. M., Clinton, S. K., ... & Kovacs, C. S. (2011). The 2011 Dietary Reference Intakes for Calcium and Vitamin D: what dietetics practitioners need to know. Journal of the Academy of Nutrition and Dietetics, 111(4), 524-527.
Fairbairn, K. A., Ceelen, I. J., Skeaff, C. M., Cameron, C. M., & Perry, T. L. (2017). Vitamin D3 Supplementation Does Not Improve Sprint Performance in Professional Rugby Players: A Randomised, Placebo-Controlled Double Blind Intervention Study. International journal of sport nutrition and exercise metabolism, 1-24.
