Vitamin D has long been known to support bone health. But new studies reveal that this vitamin plays many important roles beyond bone health. Recent scientific evidence suggests that vitamin D plays a vital role in maintaining innate immunity, protecting cardiovascular health, and protecting cells, among numerous other health benefits. Emerging data shows that vitamin D deficiency may contribute to the development of various chronic diseases, including cardiovascular disease, hypertension, diabetes mellitus, some inflammatory and autoimmune diseases, and certain cancers.
Dietary sources of vitamin D are generally limited to fortified foods and a few animal sources such as fish and eggs. Vitamin D is naturally produced in the body through exposure to direct sunlight; however, not everyone will manufacture the needed amounts with sun exposure. For example, people with darker skin tone, the elderly, and those living in northern latitudes may not produce an adequate supply of the sunshine vitamin.
The American Academy of Pediatrics (AAP) has recently doubled its recommendation for the minimum amount of vitamin D that children should get daily. The new guidelines recommend at least 400 international units (IU) daily. That’s roughly equivalent to the amount of vitamin D found in four 8-ounce glasses of milk. But most children don’t drink enough milk to receive adequate levels of vitamin D. The AAP states that the best way to ensure that children receive adequate vitamin D is through supplementation.
Two recent studies have highlighted the need for vitamin D supplementation in children. A study published in the journal Pediatrics concluded that even children who live in sunny climates aren’t getting enough vitamin D. Researchers found that a low vitamin D status is prevalent among adolescents living in year-round sunny climates in the southeastern United States. The researchers also compared vitamin D status in African American and Caucasian adolescents and found that African American youths were particularly low in vitamin D. They also found that low levels of vitamin D in kids were linked to increased fat, decreased physical activity, and lower fitness levels.
Another recent study found that seven out of 10 U.S. children have low levels of vitamin D, raising their risk of bone and cardiovascular concerns. The researchers found that nine percent of the study sample, equivalent to 7.6 million children across the U.S., was vitamin D deficient, while another 61 percent, or 50.8 million, was vitamin D insufficient. “We expected the prevalence of vitamin D deficiency would be high, but the magnitude of the problem nationwide was shocking,” reported the study’s lead author. ,
The study showed that low vitamin D levels were especially common in children who were older, female, African-American, Mexican-American, obese, drank milk less than once a week, or spent more than four hours a day watching TV, playing video games, or using computers. The researchers also found that vitamin D deficiency was associated with higher parathyroid hormone levels, a marker of bone health, higher systolic blood pressure, and lower serum calcium and HDL (good) cholesterol levels, which are key risk factors for heart disease.
In the study, children who took vitamin D supplements (at least 400 IU per day) were less likely to be deficient in the vitamin. However, only four percent of the children studied actually used supplements.