Vitamin D supplementation may prevent the common cold
Maybe you have read the earlier article stating that lack of sleep will increase your risk of getting sick? Do you still find yourself outside the gym with a runny nose and swollen eyes? Maybe it is time to evaluate your Vitamin D status.
Study after study continue to add new data regarding the positive effects of vitamin D on health and performance. As with any vitamin, the most significant benefits of supplementation, is seen when you have a deficit. The daily recommendations/ recommendations in blood levels, of a vitamin is however a fairly subjective. Today, focus have shifted from preventing deficiency toward optimization of vitamin levels.
First of all, low vitamin D (25OH)D concentrations in the blood, i.e. Vitamin D deficiency, are really common in Europe and in the US, numbers varying from around 10- 80% between different populations. (1,2). Deficiency is more common in the southern part of Europe and in the elderly but there are still significant numbers of adolescents and adults lacking adequate VitD concentrations.
A low dietary intake and a low sun light exposure are the driving factors for the deficiency, the deficiency is thus increasing during the winter months (1)
A recent meta- analysis of 25 RCTs (the highest scientific validity) compared Vitamin-D supplementation to placebo on the effect of respiratory tract infections.
The study found that Vitamin D supplementation lowered the risk of getting an acute respiratory tract infection, even though not all of the participants where defined deficient by medical standards. A greater benefit was seen in those who were deficient (3). NIH recommends a daily intake of 600iu = 15mcg/ day if you are between 19-50 yo (4).
1.Lars Ovesen. Geographical differences in vitamin D status, with particular reference to European countries. Proceedings of the Nutrition Society (2003), 62, 813–821
2.Kimberly Y.Z. Forrest. Prevalence and correlates of vitamin D deficiency in US adults. Nutrition Research 31 (2011) 48–54.
3.Adrian R Martineau. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ 20