More and more research is showing just how important vitamin D is to your overall health. It is vital for the immune system, regulating inflammation, calcium absorption, and decreasing the risk for chronic diseases. It is estimated that 70 percent of the U.S. population is deficient in vitamin D.

Vitamin D is actually a hormone that the body creates naturally from diet and sunshine. Vitamin D2 (ergocalciferol) is available from plants, and vitamin D3 (cholecalciferol) is created from exposure to ultraviolet-B (UVB) rays from sunlight. The kidneys are responsible for turning these forms into calcitrol, the active form of the vitamin.

Vitamin D3, the kind synthesized from sunlight, is the most bio-available form to the body. A recent study from Denmark showed that vitamin D3 greatly increases immunity. When vitamin D deficiency is present, the body’s T cells will lie dormant and not react to a harmful invader. The T cells rely on vitamin D to become active and fight an infection, so when you are deficient, your immune system is sluggish. “When a T cell is exposed to a foreign pathogen, it extends a signaling device or ‘antenna’ known as a vitamin D receptor, with which it searches for vitamin D,” said Carsten Geisler of Copenhagen University’s department of international health, immunology and microbiology, who led the study. “This means the T cell must have vitamin D or activation of the cell will cease. If the T cells cannot find enough vitamin D in the blood, they won’t even begin to mobilize.” Current research also suggests that vitamin D is crucial for cellular health.

It seems that vitamin D deficiency makes us vulnerable to developing serious diseases over time. Maintaining a strong and vibrant immune system is something that should be practiced daily, not just when you are sick. Exercise, sunshine and a varied whole-foods diet are all effective daily tools for keeping your immune system in tip-top shape. Supplements such as medicinal mushrooms, herbs, and probiotics also benefit the immune system. For more health-enhancing dietary recommendations, visit

Author's Bio: 

Dr. Isaac Eliaz is a respected author, lecturer, researcher, product formulator, and clinical practitioner. He has been a pioneer in the field of integrative medicine since the early 1980s. Dr. Eliaz is a frequent guest lecturer on integrative medical approaches to health, immune enhancement, and cancer prevention and treatment.