Vitamin D: How to get your daily dose
Vitamin D is a vital nutrient that plays an important role in a variety of bodily functions. Its primary job is to help the body absorb calcium. Along with calcium, vitamin D helps to build bones and keep them strong. Vitamin D regulates the release of parathyroid hormone, which causes calcium from bone to be reabsorbed into the bloodstream, often resulting in weakened, brittle bones.
The body can get vitamin D three different ways – through food, sun exposure, and nutritional supplements. There are very few foods that contain vitamin D, so getting a reasonable amount of sun is important. When skin is exposed to UV rays, it triggers vitamin D synthesis to occur. However, supplementation may be necessary for individuals who are not able to get adequate UV exposure, such as those living in northern areas with little sun during winter months or in cold climates, where they must frequently cover up to stay warm.
Individuals at risk for osteoporosis may benefit from taking vitamin D and calcium supplements, however research suggests that it may be more effective to get these nutrients from actual foods. A study used postmenopausal women in a crossover design to compare the effects of taking vitamin D and calcium supplements versus ingesting these nutrients through milk and yogurt. The amount of total vitamin D and calcium that each group received was equal, and both groups showed a significant decline in calcium lost from the skeleton. When the women were in the supplement group, they actually consumed more total calcium through other foods, but only the dairy group showed an increase in bone formation. Researchers concluded that the supplements helped to curb bone loss, but consuming dairy actually helped build bone as well.
It’s clear that getting enough vitamin D is vital to good health. Therefore, it’s important to monitor vitamin D intake and make adjustments or add supplements when necessary, especially depending on the season.