A study was forwarded from the Journal of Clinical Endocrinology and Metabolism discussing the relationship between vitamin D status and muscle mass and muscle fat in young women. Vitamin D insufficiency has now reached epidemic proportions and has been linked to increased body fat and decreased muscle strength. Whether vitamin D insufficiency is also related to adipose tissue infiltration in muscle is not known. The objective of the study was to examine the relationship between serum 25-hydroxyvitamin D (25OHD) and the degree of fat infiltration in muscle.
In the conclusion they found that vitamin D insufficiency is associated with increased fat infiltration in muscle in healthy young women.
The most important question, where does vitamin D come from?
The main source of Vitamin D is sunlight. The only other place to naturally get vitamin D is from fish. From an evolutionary standpoint, many of our ancestors might have ate a limited amount of fish, as they all did not all live near the ocean. But one thing is true about our ancestors, they spent a lot of time in the sun. Studies show that people that spend a lot of time in the sun can get ten times the amount of vitamin D we get today.
Just another reason to get outside and soak up some rays, the sun is a performance enhancer and will help with muscle mass.



















Vitamin-D
I’m working on the supplement chapter for The Paleolithic Solution and I wanted to share a few goodies I’ve tracked down in my research. The first is a link to theVitamin-D Council. This is an outstanding site that draws heavily from evolutionary biology as part of the analysis of Vit-D requirements. It’s interesting, 20-30 min of summer sun exposure can produce 10,000-20,000IU of vitamin D, but yet the governmental recommendations are for an anemic 200IU. This amidst mounting evidence adequate Vit-D may help prevent everything from H1N1 flu to cancer, diabetes and autoimmunity.
If you decide to get your Vit-D the old-fashioned way and spend some time in the sun, here is a cool tool for figuring out how many hours are available at your location under varying conditions. You will just need to track down your latitude and longitude. Here isone link for finding that, and here is another.