Pretend you are a scientist, your recent study is complete, and you get to write these words:
“In summary, 25(OH)D levels were dose-dependently associated with a robust reduction in all-cause and cardiovascular mortality in subjects with the metabolic syndrome.”
Dr. G. Neil Thomas and nine colleagues at various institutions in the UK, Germany and Austria studied 1801 subjects with metabolic syndrome for up to 8 years. They measured their vitamin D levels, treated the patients with standard care, and waited for almost 8 years.
Thomas GN, O Hartaigh B, Bosch JA, Pilz S, Loerbroks A, Kleber ME, Fischer JE, Grammer TB, Böhm BO, März W. Vitamin D Levels Predict All-Cause and Cardiovascular Disease Mortality in Subjects With the Metabolic Syndrome: The Ludwigshafen Risk and Cardiovascular Health (LURIC) study. Diabetes Care. 2012 May;35(5):1158-64.
Metabolic syndrome is extremely common and usually defined by hypertension, elevated blood sugar, abdominal obesity, elevated triglycerides and decreased HDL-cholesterol. It is difficult to treat and has a high mortality rate.
The researcher’s findings were dramatic. If your vitamin D levels was above 30 ng/ml, you had a 75% reduced risk of dying from all causes, a 69% reduced risk of getting cardiovascular disease and an 85% reduction in suddenly dying, compared to those with levels less than 10 ng/ml.
Furthermore, at baseline, the subjects with levels above 30 ng/ml (only 143 of the 1801 subjects), their blood sugar, hemoglobin A1C, and C reactive protein (CRP) were all significantly (<.001) better. If your vitamin D level was less than 10 ng/ml, your CRP was about 70. If your vitamin D was greater than 30 ng/ml, your CRP was 29. As I always say, what would it have been if any of them had of had natural levels, around 50 ng/ml?
Finally, the UK, Germany and Austria are all northern countries so they should have considerable seasonal fluctuations in the vitamin D levels. However, no U-shaped curve was apparent. (“U-shaped” is when harm occurs with both low and high vitamin D levels). However, from what I understand, the UK, Germany and Austria are not cod liver oil countries. If you remember, the “U-shaped” studies have almost all come from cod liver oil countries, where they often use cod liver oil, with all the low-grade vitamin A toxicity that that implies. Indeed, a Cochrane Review found that vitamin A supplements increased total mortality rate by 16%.
Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev 2008 Apr 16;(2):CD007176.
The takeaway story is that if you have metabolic syndrome, get your vitamin D levels up to natural ranges. The authors here show that levels above 30 ng/ml are beneficial, but I believe even higher, at 50 ng/ml, would be better.