What are your vitamin D levels? If you’re not sure, getting tested — and then optimizing your levels — could help you live longer. While low vitamin D levels have long been associated with increased risk of death, data on severely deficient individuals are lacking. Now, it’s been shown that people genetically predisposed to vitamin D deficiency were 25% more likely to die from any cause compared to those with different genetics conducive to healthy vitamin D levels. Read more.