If you’re following the health news, you know that vitamin D currently is in the media spotlight, and rightly so. Will Brink just did a great podcast “Vitamin D3 – scam or panacea?“, giving an overview on the importance vitamin D. In this article I will expand upon some key points taken up in the podcast, and back up the case with a solid reference list of recent studies on the topic. I will also present some revealing prevalence stats on vitamin D insufficiency, in order to convince you to get your blood levels checked to find out your vitamin D status.

Vitamin D is interesting for several reasons:

1. The role of vitamin D for health promotion has undergone a paradigm shift. While traditionally thought to only be important for development and maintenance of strong bones, an impressive body of scientific research has accumulated over the past decade, showing that adequate vitamin D levels are necessary to prevent many diseases, especially cardiovascular disease, high blood pressure, endothelial dysfunction, diabetes (both type-1 and type-2), the metabolic syndrome, chronic inflammation, cancer, osteoporosis (including falls and fractures), muscle weakness, cognitive dysfunction and mental illness, autoimmune diseases (e.g. multiple sclerosis, rheumatoid arthritis), infectious diseases, as well as infertility and adverse pregnancy and birth outcomes [1-24].

Vitamin D deficiency/insufficiency is associated with all-cause mortality [1], and supplementation has been shown to decrease mortality rates [25, 26]. It has been estimated that doubling vitamin D levels in the general population (from 21 ng/mL to 44 ng/mL) would reduce  vitamin D-related disease mortality rate by 20%, and increase life expectancy with about 2 years [27].

2. Insufficient levels of vitamin D also have direct implications for fitness enthusiasts and athletic performance, due to the importance of vitamin D for muscle function (I will cover this in much more dept in an upcoming article) [28-39].

3. In contrast to other vitamins, vitamin D deficiency/insufficiency is very common (more on that below).

4. The vitamin D requirement for health promotion and protection against the mentioned diseases and muscle dysfunction is much higher than the dietary recommendations (RDA) for bone health [4, 40-45].

Having heard about all the vitamin D benefits you might wonder what is the optimal vitamin D level? How low is too low and how high is too high?  How much vitamin D does one have to consume to reap all the benefits? Let’s find out…