Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...Tell Me More
“In the winter months, when the sun’s rays are not intense enough to generate sufficient vitamin D production (this is the case for three to five months per year for locations in North American—you know it’s downtime for D when you can’t get a tan even with prolonged sun exposure), supplements and safe-designated artificial tanning implements can be useful or even essential if you are at high risk for deficiency.
If you have an indoor-dominant lifestyle or even a hint of aforementioned risk factors, you should regularly test your blood for vitamin D. (Make sure it’s for ’25-vitamin D’ or ‘serum 25(OH)D.’ You can order this test directly from an online provider like direct labs.com. or, if you are getting a routine checkup, insist they include vitamin D in your blood panels. (Unfortunately, it’s often not included.)”
—From The New Primal Blueprint
For more on vitamin D sources, deficiency, testing and recommended levels, see The New Primal Blueprint or check out past articles on MDA.