Vitamin D, which is primarily provided to the body by the sun, has been a hot topic in the U.S. lately. The federal standards for vitamin D intake have come under fire by public health professionals as being much too low, and disagreement continues over the proper amount of vitamin D necessary for optimal health.
Accumulation of abdominal fat, or central fat, may lead to a so-called apple body shape, which is commonly linked to increased risks of type 2 diabetes, heart disease and other chronic conditions later in life, says epidemiologist Eduardo Villamor, associate professor at the U-M School of Public Health and senior author of the study.
Villamor worked with colleagues at the National University of Colombia and began the research while at Harvard. The investigators recruited a group of 479 school children ages 5-12 from Bogota, Colombia, in 2006 and followed them for about 30 months. They measured vitamin D in blood taken at the beginning of the study, and then examined the link between vitamin D levels and changes in three indicators of body fat over time: body mass index, waist circumference and subscapular-to-triceps skin fold ratio.
"We found that the kids with the lowest vitamin D levels at the beginning tended to gain weight faster than the kids with higher levels," said Villamor, who added that children with the lowest vitamin D levels had more drastic increases in central body fat measures.
Vitamin D deficiency was also linked to slower growth in height among girls but not boys, he said.
"Our findings suggest that low vitamin D status may put children at risk of obesity," said Diane Gilbert-Diamond, Villamor's former Harvard student, now at Dartmouth Medical School and first author of the study. "This is significant because vitamin D insufficiency is highly prevalent across the globe and childhood obesity rates are dramatically increasing worldwide."
Though vitamin D intake could be related to early obesity, it's just part of a very complex picture, Villamor stressed.
Of all the children tested, 10 percent were vitamin D deficient, and another 46 percent of kids were insufficient, which meant they were at risk of becoming deficient.
"Interestingly, Bogota, Colombia, is in a subtropical zone where one may not expect to find a lot of vitamin D deficiency since the assumption is that sunlight is abundant there, but there could be many reasons people in subtropical climates may not get enough sun exposure," Villamor said.
Indeed, previous studies have shown that populations in other subtropical areas such as Sao Paulo, Brazil, and Costa Rica may also have vitamin D deficiency.
"These findings should motivate some discussion on ways to enhance vitamin D status of children there, although it will be necessary to confirm in intervention studies whether improvements in vitamin D status decrease the risk of childhood obesity and early development of chronic diseases," Villamor said.
In addition to sun exposure, other sources of vitamin D are fortified foods and supplements. Vitamin D supplementation has been shown to prevent some viral infections in school-age children, so there could be benefits on other outcomes as well, which need to be tested in future studies, Villamor pointed out.
The paper, "Vitamin D deficiency and anthropometric indicators of adiposity in school-age children: a prospective study," is available this month in the American Journal of Clinical Nutrition.
The University of Michigan School of Public Health has been promoting health and preventing disease since 1941, and is ranked among the top public health schools in the nation. Whether making new discoveries in the lab or researching and educating in the field, SPH faculty, students and alumni are deployed around the globe to promote and protect our health. Visit: www.sph.umich.eduContact: Laura Bailey
Laura Bailey | EurekAlert!
Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center
Study advances gene therapy for glaucoma
17.01.2018 | University of Wisconsin-Madison
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
18.01.2018 | Life Sciences
18.01.2018 | Life Sciences
18.01.2018 | Earth Sciences