Great article summarizing the importance of Vitamin D in our diets. While RDA’s have been based upon bone health, we are learning that higher levels may be helpful for reducing risk of cancer, depression, fatigue, and supporting immune function. I generally recommend 1,000 – 2,000 IU of Vit. D3 daily, depending upon each individual’s health status. I also monitor Vitamin D levels in the blood to reduce risk of over-dosing.