Adolescentes em perigo devido a epidemia de baixos níveis de vitamina D
Teens in Danger from Epidemic of Low Vitamin D
This week at the American Heart Association’s 49th Annual Conference on Cardiovascular Disease Epidemiology and Prevention, Jared P. Reis, Ph.D., and his team of researchers at Johns Hopkins Bloomberg School of Public Health in Baltimore announced their findings of a study of 3,577 adolescents, 12 to 19 years old (51 percent boys), who participated in the nationally representative National Health and Nutrition Examination Survey (NHANES) conducted from 2001. The scientists used a biomarker in the research subjects’ blood to measure vitamin D obtained from food, vitamin supplements and exposure to sunlight.
"We showed strong associations between low levels of vitamin D and higher risk of high blood pressure, hyperglycemia and metabolic syndrome among adolescents, confirming the results of studies among adults," Dr. Reis said in a statement to the media. Low levels of vitamin D could also help explain why American teens are becoming fatter. A lack of the vitamin is strongly associated with being overweight and obesity centered around the abdomen, Reis noted.
Specifically, the youngsters with the lowest levels of vitamin D were 2.36 times more likely to have hypertension, 2.54 times more likely to have high blood sugar and about 4 times more likely to have metabolic syndrome — a group of cardiovascular disease and diabetes risk factors that includes an increased waist circumference, high blood pressure, elevated triglycerides, low levels of high-density lipoprotein (HDL or "good") cholesterol and high fasting glucose levels.
But how wide-spread is the lack of vitamin D in teens? Another study by researchers in the Department of Public Health at Weill Cornell Medical College published in the March issue of the journal Pediatrics gives the answer — about one in 7. Girls were found to have twice the risk of vitamin D deficiency than boys. What’s more, overweight teens had nearly double the risk of being vitamin D deficit than their counterparts of normal weight.
The study used new criteria of vitamin D deficiency recommended by a group of scientists who worked together at the 13th Workshop Consensus for Vitamin D Nutritional Guidelines in 2007 and concluded the minimum acceptable serum vitamin D level should be raised from 11 nanograms per milliliter (ng/mL) to at least 20 ng/mL. Using this definition, the study found more than half of African-American teens are vitamin D deficient.
"These are alarming findings. We need to do a better job of educating the public on the importance of vitamin D, and the best ways to get it. To meet minimum nutritional requirements teens would need to consume at least four glasses of fortified milk daily or its dietary equivalent. Other foods rich in vitamin D include salmon, tuna, eggs and fortified cereals. A vitamin supplement containing 400 IU of vitamin D is another alternative," said researcher Dr. Sandy Saintonge, assistant professor of clinical pediatrics and assistant professor of clinical public health at Weill Cornell Medical College, in a statement to the media.
Getting enough sunshine is also a healthy way to boost levels of the vitamin. According to the National Institutes of Health (NIH) web site, approximately 5 to 30 minutes of sun exposure between 10 AM and 3 PM at least twice a week to the face, arms, legs, or back without sunscreen usually leads to sufficient vitamin D synthesis.
About the author
Sherry Baker is a widely published writer whose work has appeared in Newsweek, Health, the Atlanta Journal and Constitution, Yoga Journal, Optometry, Atlanta, Arthritis Today, Natural Healing Newsletter, OMNI, UCLA’s "Healthy Years" newsletter, Mount Sinai School of Medicine’s "Focus on Health Aging" newsletter, the Cleveland Clinic’s "Men’s Health Advisor" newsletter and many others.