Vitamin D Levels Low Among People in U.S., Particularly Those With Darker Skin, Study Finds
Levels of vitamin D have decreased dramatically among people in the U.S., and those with darker skin tend to have more acute deficiencies, according to a study in the Archives of Internal Medicine, Indiawest.com reports. The study -- by Adit Ginde, an assistant professor at the University of Colorado-Denver School of Medicine, and colleagues -- surveyed 18,863 people, including several ethnicities.
Vitamin D deficiency might be on the rise due to more people avoiding the sun to prevent skin cancer. The condition has been linked to rickets and osteoporosis, and the vitamin is believed to play a role in cardiovascular health and healthy immune systems.
According to Ginde, an abundance of the skin pigment melanin, which is prevalent in those with darker skin, can block ultraviolet light, which induces vitamin D production. Vitamin D deficiency is particularly prevalent among blacks and Hispanics. Three percent of blacks had sufficient levels of vitamin D in 2004, Indiawest.com reports. He added, "Indian Americans are at fairly high risk for vitamin D deficiency, depending on their skin color."
Ginde said that those with lighter skin can boost vitamin D levels by getting 10 to 15 minutes of sun daily, while those with darker skin need about five times that amount. People also can boost vitamin D through dietary sources, such as fatty fish, fortified milk and supplements, though darker-skinned people need twice the amount as those with lighter skin (Sohrabji, Indiawest.com, 4/6).
An abstract of the study is available online.