Vitamin D
Vitamin D come in two forms: Vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D3 has much greater bioavailability and is the form that is effectively used by the body.  This supplement provides cholecalciferol. Clinical trials show the following effects of vitamin D:

• Prevent Bone Disorders*: When vitamin D is low, bone breakdown occurs to satisfy the body’s demand for calcium. Maintaining healthy vitamin D prevents rickets, osteoporosis, and osteopenia.
• Prevent Muscle Weakness & Decrease Falls*: Low vitamin D leads to muscle weakness and increases risk of falling in all populations, including athletes and the elderly.
• Support Immune Function*: Vitamin D improves the number and function of immune cells that fight off disease.
• Improve Testosterone In Men*: Vitamin D inhibits the enzyme aromatase that transforms testosterone to estrogen.
• Support Cardiovascular Health*: Adequate vitamin D decreases calcification of the arteries, reducing stress on the heart. A deficiency is consistently linked with increased risk of death by heart attack.
• Support Neurological Function*: Vitamin D modulates calcium channels in the brain that control cellular brain health, affecting memory.
• Reduce Cancer Risk*: Vitamin D is inversely correlated with increased risk for a variety of cancers, including breast, colon, prostate, and pancreatic cancer.
• Support Healthy Body Composition*: Vitamin D is fat soluble and gets sequestered in fat tissue, increasing the risk of vitamin D deficiency in obesity.
• Improve Metabolic Health*: Vitamin D supplementation improves insulin sensitivity and glucose tolerance in people with vitamin D deficiency.
• Reduce Mortality & Disease*: Low vitamin D is independently associated with many diseases and an increased risk of dying from all causes. Supplementation reduces all-cause mortality in the elderly.