Vitamin D – The Sunshine Vitamin

Vitamin D is a fat-soluble vitamin that plays an important role in the absorption of calcium and phosphorus from food. It is necessary for healthy, strong bones and teeth and may aid in the prevention of osteoporosis. Studies suggest that it may also help decrease the risk of breast, colon and ovarian cancer, coronary disease, type-2 diabetes, hypertension, inflammation as well as support heart health.

There are two common types of vitamin D. D2 (ergocalciferol) is derived from plant sources and D3 (cholecalciferol) is derived from animal sources. D3 is the form of vitamin D that your body makes when exposed to direct sunlight. Both plant-derived D2 and animal-derived D3 will prevent deficiency, although there is a controversy as to whether or not D3 is a superior form of Vitamin D, as is generally believed. A recent study by the Boston University School of Medicine indicated that vitamin D2 was just as effective as D3 in maintaining adequate levels in the body.

Vitamin D Foods and Sources

Your body synthesizes vitamin D when your skin is exposed to direct sunlight. Generally, 10-15 minutes of sunlight on the face and arms when the UV index is greater than 3 provides an adequate amount. Those with darker skin pigmentation may need longer exposure. In temperate regions (like much of the United States and Canada), adequate sunlight exposure is difficult or impossible during the winter months (November through February).

Basically, the further away you live from the equator impacts your ability to synthesize enough vitamin D from sunlight alone. Your ability to create vitamin D from sunlight is also greatly reduced by cloud cover, smog and the use of sunscreen.

There are few natural foods which have vitamin D, and most are fortified with the vitamin. For vegans and vegetarians, your best bet for getting adequate amounts of vitamin D in the winter months is through UV irradiated mushrooms. Mushrooms synthesize vitamin D in much the same way that humans do though exposure to sunlight but in the form of vitamin D2. Alternate sources are vitamin D fortified cereals, milks (soy, rice, almond) and supplements. Vegans should be aware that vitamin D3 (cholecalciferol) supplements or fortified foods contain ingredients derived from animal origins and may be found in foods that are labeled “vegetarian” or “meat-free”.

Vitamin D Deficiency

Vitamin D deficiency causes brittle, thin bones and is believed to increase risk of high blood pressure, tuberculosis, cancer, periodontal disease, multiple sclerosis, chronic pain, seasonal affective disorder (SAD), peripheral artery disease, cognitive impairment, memory loss and autoimmune diseases such as type 1 diabetes. In children, rickets may result causing stunted growth and deformity. Vitamin D deficiency may contribute to the development of osteoporosis.

Vitamin D may be deficient if you get inadequate sunlight and/or consume inadequate amounts of healthy dietary fat.

Vitamin D Toxicity

Vitamin D toxicity is rare among those with a normal diet but is possible with excessive supplement use with symptoms that include loss of appetite, nausea, vomiting, high blood pressure, kidney malfunction and “failure to thrive” in children.

The Effects of Cooking On Vitamin D

Vitamin D appears to be stable when exposed to heat, air and UV light.

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