Vitamin D and Type 2 diabetes

Interesting further info re the link between Vitamin D and type 2 diabetes.  There is also a link to type 1 with Nordic countries having low sunshine levels and an increased incidence of type 1.  No plausible mechanism as this is an observational study only so can only ever show association.  Interesting that the individuals came from southern California where it must be hard to find individuals who have a low level of vitamin D!

MEDSCAPE REPORT

People with low vitamin D levels may be at increased risk of type 2 diabetes, according to the results of a new US epidemiological study.

The analysis of more than 900 individuals from southern California found that having plasma levels of 25-hydroxyvitamin D (25[OH]D) greater than 30 mg/mL was associated with a significant and substantial reduction in later diabetes risk.

"We found that participants with blood levels of 25-hydroxyvitamin D that were above 30 ng/mL had one third of the risk of diabetes, and those with levels above 50 ng/mL had one fifth of the risk of developing diabetes [compared with those whose levels were < 30 ng/mL]," said lead author Sue K Park, MD, Seoul National University College of Medicine, South Korea, in a press release by the University of California, San Diego (UCSD), where some of the team are based.

The research, published online April 19 in PLoS One, also showed that every 10 ng/mL increase in 25(OH)D levels above 30 ng/mL was associated with a 36% reduction in diabetes risk.

However, second author Cedric F Garland, DrPH, of UCSD, emphasized that the epidemiological nature of the study means the findings are not able to demonstrate causality.

"Further research is needed on whether high 25-hydroxyvitamin D levels might prevent type 2 diabetes or the transition from prediabetes to diabetes. But this paper and past research indicate there is a strong association," he said.

Examining the Issue at the High End of Normal Median Vitamin D Levels

In their article, Park and colleagues note that higher plasma 25(OH)D levels have previously been associated with a lower risk of type 2 diabetes.

see http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0193070

for further information..