Vitamin D is a fat-soluble vitamin that can be obtained through the diet or synthesized in the skin upon exposure to sunlight. Vitamin D3, the form of vitamin D formed in the skin, is a potent and active form of the vitamin. Vitamin D2 is a vitamin D analog formed in plants, mushrooms and yeasts during photosynthesis. While vitamin D2 is sometimes used in food fortification, Puritan’s Pride supplements provide the active form.

Vitamin D plays a regulatory role in the growth, differentiation, and proliferation of different types of white blood cells.^8* It is important to regulate these processes to maintain immune balance. Think of a thermostat set to 70 degrees.

When the temperature falls below 70 degrees the heat comes on but once the temperature is reached, the heat needs to turn off or else the temperature will continue to rise indefinitely. The same delicate balance is needed for our immune systems to maintain optimal health.

The T and B cells of the adaptive immune system are both regulated by vitamin D.^* Many cells of the innate immune response also require vitamin D such as monocytes which need it to mature properly.^* Adequate concentrations of vitamin D are also necessary for the synthesis of important proteins with immune-fighting properties.