We have known for a long time that vitamin D is important for our health. Recently scientists discovered that it helps us stave off heart disease and regulate our diabetes. But until now they couldn't tell us how much vitamin D we need to get each day to help us manage our blood sugar levels.
The Sunshine Vitamin on the Yellowstone River
Just a week ago I pointed out in my most recent article here, "Best Vitamin D Choices for Diabetes," that "the experts still haven't decided on precisely how much vitamin D we need." They just did.
Researchers from the University of Maryland and the U.S. Department of Veterans Affairs led by Drs. John Sorkin and Andrew Goldberg have now studied the relationship between circulating vitamin D concentration and measures of health, specifically our blood sugar levels. The American Society for Nutrition first published this research report online April 9, 2014, and will print it in the May 2014 issue of The Journal of Nutrition. The full text of the study, "Evidence for Threshold Effects of 25-Hydroxyvitamin D on Glucose Tolerance and Insulin Resistance in Black and White Obese Postmenopausal Women," is free online.
The findings come as a surprise. The surprise is a good one, because we don't need to get as much vitamin D as some experts thought we needed -- at least for blood sugar regulation. The new study "found evidence for a threshold effect" of a level about 26 ng/ml.
A review, "Vitamin D and Diabetes," in The Diabetes Educator that I cited in my article here five years ago on "Vitamin D Testing" put the normal level at 30 to 60 ng/ml. GrassrootsHealth recommends a level of 40 to 60 ng/ml.
The new 26 ng/ml value is also lower than that recommended by the Endocrine Society, 30 ng/ml. It is higher than that recommended by the Institute of Medicine, 20 ng/ml. But these organizations were looking at bone health rather than blood sugar regulation in setting those levels.
Vitamin D levels of up to 60 ng/ml may still make sense for some of the conditions that it helps. My most recent level was 68 ng/ml, and I intend to keep it close to that range by continuing to take 5,000 IU of vitamin D3 every day.
The researchers of the new study of 239 healthy, nonsmoking, postmenopausal women found that those who had high levels of vitamin D had lower body fat and circulating glucose, insulin, and triglyceride levels than the women who had low levels. They also regulated their blood sugar better. But those who had levels above 26 ng/ml didn't get any additional benefits in these respects.
How can you use this new information? If you don't already know your level, the place to start is to get your vitamin D level tested, something that I don't think that our doctors routinely do for us.
If you ask, your doctor will probably send you to a local lab for testing. Another option is a home test kit from GrassrootsHealth.
When you find out your level, I suggest that you take another look at last week's article here, "Best Vitamin D Choices for Diabetes." One of our choices is to get more sunshine. After all, we don't call it the sunshine vitamin for nothing. Some other choices may be just as good. For most of us, getting a little more vitamin D in our systems will help us bring down our blood sugar.