I've been following Dr.William Davis' blog and he often emphasizes on the importance of Vitamin D for good health, as has Mark. I have never been tested for Serum Vit D level and other than cod-liver oil capsules that I have started taking only recently, I don't take any Vit D supplements. My question: How many of you have been tested for D levels in your blood and do you take any supplements to maintain the normal level? I would love to learn more. And have my mother, who is on statins, take them too. Thoughts and recommendations will be much appreciated.