Got Vitamin D? It Might Prevent Diabetes
I’ve spoken many times about the importance of the so-called “sunshine vitamin,” vitamin D. It’s extremely important for numerous important aspects of overall health. So much so that our bodies have developed a mechanism to make this important hormone, under certain conditions. Specifically, the bare skin must be exposed to sunlight sufficiently strong (late spring through late fall in most parts of North America) for at least 10 - 15 minutes a day, two to three times per week.
Unfortunately, many things about modern life prevent this natural process from taking place. For one, there’s the problem of winter sunlight. In winter, in most of North America, sunlight is simply too weak to do us any good. But even when it warms, and sunlight strengthens, few of us are likely to spend time out of doors, with exposed skin—and no sunscreen on. Aging, excess body weight, and having naturally dark skin all contribute to inefficiency with the ultraviolet light-driven process of generating natural vitamin D.
This is one of the reasons we’ve been adding vitamin D, in fairly small amounts, to dairy products for decades. Scientists recognized that some kids weren’t getting enough vitamin D to prevent rickets—a brittle bone disease related to insufficient vitamin D in childhood. But rickets represents the far end of the spectrum when it comes to the potential negative side effects of too little vitamin D. Other, more subtle problems may also be linked to insufficient vitamin D.
In recent decades it’s become increasingly clear that vitamin D is crucial for a strong, functional immune system. It’s also important for cardiovascular and brain health. Now, scientists say, it’s apparent that inadequate vitamin D levels may also increase one’s risk of developing type 2 diabetes. That’s especially alarming, because research has repeatedly demonstrated that a majority of Americans have either insufficient, or even deficient, levels of vitamin D. And type 2 diabetes is something of a national epidemic.
Doctors have long noted an apparent relationship between obesity and diabetes. But new research suggests that having low vitamin D levels may be more closely linked to the risk of developing diabetes than obesity. The advantage of this study, conducted in Europe, was that subjects were all shapes and sizes. Some obese people had normal levels of vitamin D. They tended not to show signs of diabetes. Others were thin, but had low vitamin D levels. They were surprisingly more likely to have signs of diabetes.
"Our findings indicate that vitamin D is associated more closely with glucose metabolism than obesity," said one of the study's authors, Manuel Macías-González, PhD. ”The study suggests that vitamin D deficiency and obesity interact synergistically to heighten the risk of diabetes and other metabolic disorders. The average person may be able to reduce their risk by maintaining a healthy diet and getting enough outdoor activity.”
Kumar J, Muntner P, et al. Prevalence and associations of 25-hydroxyvitamin D deficiency in US children: NHANES 2001-2004. Pediatrics. 2009 Sep;124(3):e362-70. doi: 10.1542/peds.2009-0051. Epub 2009 Aug 3.
Mercedes Clemente-Postigo, Araceli Muñoz-Garach, Marta Serrano, Lourdes Garrido-Sánchez, M. Rosa Bernal-López, Diego Fernández-García, Inmaculada Moreno-Santos, Nuria Garriga, Daniel Castellano-Castillo, Antonio Camargo, Jose M. Fernandez-Real, Fernando Cardona, Francisco J. Tinahones, Manuel Macías-González. Serum 25-Hydroxyvitamin D and Adipose Tissue Vitamin D Receptor Gene Expression: Relationship With Obesity and Type 2 Diabetes. The Journal of Clinical Endocrinology & Metabolism, 2015; jc.2014-3016 DOI: 10.1210/jc.2014-3016