Vitamin D is commonly referred to as the sunshine vitamin, as it is produced in the body with mild sun exposure or obtained through consumption of supplements or food.
Adequate amounts of vitamin D intake is important for regulation of calcium and phosphorus absorption, the overall maintenance of healthy bones and teeth and assists in combating multiple diseases such as type 1 diabetes and multiple sclerosis.
- Vitamin D has multiple roles in the body, helping to:
- Maintain the health of bones and teeth
- Support the health of the immune system, brain and nervous system
- Regulate insulin levels and aid in diabetes management
- Support lung function and cardiovascular health
Despite its name, vitamin D is considered to be a pro-hormone and not actually a vitamin. This is because the body is capable of producing its own vitamin D through the action of sunlight on the skin, while vitamins are nutrients that cannot be synthesized by the body and must be acquired through diet or supplements.
It is estimated that sensible sun exposure on bare skin for 5-10 minutes 2-3 times per week allows the body the ability to produce sufficient vitamin D, but vitamin D has a half-life of only two weeks, meaning that stores can run low, especially in winter.
Vitamin D plays a substantial role in the regulation of calcium and maintenance of phosphorus levels in the blood, two factors that are extremely important for maintaining healthy bones. We need vitamin D to absorb calcium in the intestines and to reclaim calcium that would otherwise be excreted through the kidneys. In adults, vitamin D deficiency manifests as osteomalacia or osteoporosis. Osteomalacia results in poor bone density, muscular weakness and often causes small pseudo fractures of the spine, femur and humerus. Osteoporosis is the most common bone disease among post-menopausal women and older men.
Pregnant women who are deficient in vitamin D seem to be at greater risk of developing preeclampsia and needing a cesarean section. Poor vitamin D status is also associated with gestational diabetes mellitus and bacterial vaginosis in pregnant women. It is also important to note that vitamin D levels that were too high during pregnancy were associated with an increase in food allergy of the child during the first two years of life.
Sunlight is the most common and efficient source of vitamin D. The richest food sources of vitamin D are fish oil and fatty fish. Here is a list of foods with good levels of vitamin D:
- Cod liver oil, 1 tablespoon
- Herring, fresh, raw
- Swordfish, cooked
- Raw maitake mushrooms
- Salmon, sockeye, cooked
- Sardines, canned
- Fortified skim milk
- Tuna, canned in water, drained
- Egg, chicken, whole large