NSI Vitamin D3 (as Cholecalciferol) supports maintenance of healthy bones and teeth. Supports cellular health and proper nervous system and immune function. What is NSI Vitamin D3 (as Cholecalciferol)? The same form of vitamin D that the body manufactures when skin is exposed to ultraviolet radiation from the sun. A good source of Vitamin D as few natural foods contain Vitamin D in sufficient quantity to meet Daily Value levels. A superior nutrient to Vitamin D2 as Vitamin D3 may be more than three times as effective as in raising concentrations of Vitamin D in the bloodstream and maintaining those levels for a longer time.*. Why choose NSI Vitamin D3 (as Cholecalciferol)? Vitamin D contributes to bone strength as proper levels create optimum conditions for bone formation.*. Vitamin D supports the proper functioning of the nervous and immune systems.*. Vitamin D contributes to healthy levels of phosphorous in the body. *. Vitamin D promotes the intestinal absorption of the calcium.*. Vitamin D supports fetal skeletal development and tooth enamel formation.*. Provides exceptional quality at extraordinary value. About NSI®. All Nutraceutical Sciences Institute products are laboratory tested to meet FDA standards for identity purity and composition. All products are tested for heavy metals microbiology and contaminants which may be present. Every batch is laboratory tested to guarantee freshness and purity levels. All products manufactured at Nutraceutical Sciences Institute are produced in an NSF Certified facility.  .  .  . * These statements have not been evaluated by the Food and Drug Administration.  This product is not intended to diagnose treat cure or prevent any disease.