Low vitamin D levels, higher type 2 diabetes risk
In a study headed by Professor Garland and published in PLoSOne, 903 healthy adults enrolled in the Rancho Bernardo Study. The average age of the participants was 70, and none of these volunteers had prediabetes or diabetes when they began the study in 1997-1999.
The participants gave blood samples to enable the researchers to assess the vitamin 25(OH)D levels. A follow-up study in 2009 listed 7 cases of type 2 diabetes and 337 cases of prediabetes.
Professor Garland claims that the risk of developing type 2 diabetes in those vitamin D or 25(OH)D blood levels lower than 30 nanograms per milliliter of blood was more than five times that of those whose 25(OH)D blood levels were higher than 50 nanograms per milliliter.
To reach the optimum blood level of 30 nanograms per milliliter, you would need to take approximately 3,0000 to 5,000 IU of vitamin D every day. In order to lower the number of supplements you need by going out in the sun at least 10-15 minutes per day.