Most of us think of vitamin D as the "vitamin from the sun." But did you know that vitamin D is actually a hormone? Hormones function as chemical messengers in the body. Vitamin D is made in the body from cholesterol. When the skin is exposed to the sun, the body goes to work to form active vitamin D. But if liver function or metabolism is comprised, this can effect how much vitamin D is produced. Cells throughout the body have vitamin D receptors that have a wide range of effects. Vitamin D3 can also be obtained from food, like fatty fish, liver eggs, and fortified dairy products, but these sources have a relatively small amount. Salmon, for example provides approximately 350 IU of vitamin D per serving.
Vitamin D deficiency is now recognized as a pandemic, which means it has become widespread around the world. In the United States, data from 2006 National Health and Nutrition Examination Survey suggest We know that sun exposure in moderation is the major source of vitamin D for most humans. Risk factors for vitamin D deficiency are premature birth, darker skin pigmentation, low sunshine exposure, obesity, poor absorption of nutrients and advanced age. Vitamin D deficiency compromises bone strength, can cause rickets in children, increase the risk of osteoporosis and fractures and more recently deficiency has been linked to increased risk of certain cancers, autoimmune diseases, high blood pressure, heart disease, type 2 diabetes, and frequent colds.
To help protect yourself and prevent being deficient, there are several steps you can take. First, you can ask your health care provider to measure your vitamin D levels. Your levels should be at or above 40 ng/mL. Another step you can take (and talk to your dermatologist first) is either 10-15 minutes per day of full body summer midday sun bathing. And finally, you can eat fatty fish or supplement Vitamin D3.