نظرة عامةBone & Immune SupportDietary SupplementResearch suggests that Vitamin D may be your single most important supplemental nutrient. Required for optimal calcium absorption, vitamin D promotes strong bones and is vital support for a healthy immune system.Vitamin D is obtained from the diet or from sun exposure. However, vitamin D is not abundant in foods and people are increasingly avoiding the sun. This high-potency supplementation is necessary to ensure healthy levels of this key nutrient.