Vitamin D3 4000 IU - 120 softgels

Vitamin D functions as a hormone, and every single cell in the body has a receptor for it. The human body produces it from cholesterol when your skin is exposed to sunlight, but sunscreen, protective clothing, limited sun exposure, dark skin, and age can hinder getting enough vitamin D from the sun. It is also found in some foods, such as fatty fish and fortified dairy products, although it is very difficult to get enough from diet alone. The recommended daily allowance (NRV) is usually around 400–800 IU.