Vitamin D at Research Forefront

WASHINGTONResearchers continue to churn out new studies analyzing vitamin D's positive effects on various health issues, spanning from Parkinson's to neonatal outcomes.

The first two studies, published in the American Journal of Clinical Nutrition, looked at vitamin D's role in adolescent obesity and Parkinson's disease. In the first trial, researchers from the University of Missouri School of Medicine investigated vitamin D deficiency in obese adolescents, as poor vitamin D status is associated with increased prevalence of metabolic syndrome and type-2 diabetes (Am J Clin Nutr. April 2013). The study found 4,000 IU of vitamin D3 daily improved insulin resistance in the teens, but had no significant differences in body mass index (BMI), inflammatory markers or plasma glucose concentrations.

The second study, conducted by scientists at Jikei University School of Medicine, Tokyo, Japan, found vitamin D3 supplementation stabilized Parkinson's disease in patients with particular genotypes without triggering hypercalcemia (Am J Clin Nutr. May 2013 ajcn.051664).

The sunshine vitamin may have healthy benefits for the opposite end of the age spectrumbabies. A meta-analysis published in the British Medical Journal assessed vitamin D levels and pregnancy outcomes, linking vitamin D deficiency to an increased risk of gestational diabetes, pre-eclampsia, and small for gestational age infants (BMJ 2013; 346:f1169). Women with low vitamin D levels were also more likely to have lower birth weight babies and bacterial vaginosis.

Vitamin D deficiency was also tied to cancer predisposition in smokers, according to a study in Clinical Chemistry. In the large-scale study, Danish researchers followed nearly 10,000 individuals from the Copenhagen City Heart Study, all of whom were cancer-free at baseline (Clin Chem. March 2013; doi: 10.1373). Patients who developed tobacco-related cancer averaged a vitamin D concentration of 14.8 ng/mL, compared to the 16.4 ng/mL average measurement for the entire study population. Scientists found lower plasma vitamin D levels was associated with a higher risk of tobacco-related cancers, but not with other types of cancer.

Earlier this month, a Korean study suggested vitamin D may improve lung function and protect against tuberculosis (TB), while Boston University researchers found improved vitamin D status significantly affected gene expression associated with cancer, autoimmune disorders and cardiovascular disease (CVD).