Martin Gaksch, et al.

Medical University of Graz, Austria

PLoS ONE

February 2017

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What did they do?

This study is a meta-analysis, which means it is a study of other studies - they combine and analyze data from several previously conducted studies. In this case, the authors standardized individual participant vitamin D levels from eight independent studies for their analysis on vitamin D and mortality.

The data came from 26,916 European individuals with a median age of 61.6 years, 58% females, and a median 25(OH)D of 53.8 nmol/L (about 20 ng/ml).

How did they measure the results?

Study subjects were grouped into different ranges of baseline 25(OH)D measurement and death rates were compared between those ranges. The groupings were

 

The biggest difference in mortality was seen in the comparison between the lowest category (< 12 ng/ml) and those in the middle sufficient category (30-40 ng/ml). Those in the lowest category were 1.67 times more likely to die than those in the higher category.

No J-shaped curve

This study created the top 2 sufficient groups (30-40 ng/ml and 40-50 ng/ml) because in the past they were the regions that would sometimes show decreased benefit - the area where the graph would take an uptick - the back half of the U or J-shaped curve.

The study population had most people < 30 ng/ml (22940, 85%). The largest group > 30 ng/ml was the first one - 30-40 ng/ml with 3125 people. The next two groupings had 679 and 172 people respectively. (Table 2 in paper). The risk for all-cause mortality was not significantly different in any of the groups above 20 ng/ml (50 nmol/L) - no J-shaped curve!

Figure 1 from paper

Cardiovascular Death

Cardiovascular death was also considered in these same groupings (the two highest were combined). Those with the lowest vitamin D levels, < 12 ng/ml, were 3.18 times more likely to die of cardiovascular related causes than those in the reference range of 30-40 ng/ml. As shown in table 3 of the paper, there was a continued decrease in cardiovascular death as vitamin D levels increased.

Cancer

The authors did not find a linear relationship between vitamin D and cancer - the cancer rate did not consistently go down as vitamin D levels increased, but, as shown in table 4 of the paper, all groups lower than the reference group of 30-40 ng/ml had a higher risk, and those in the highest group, >40 ng/ml, had a lower risk. Again, no sign of a J-shaped curve.

This data is consistent with previous research from Dr. Cedric Garland who has long noted that women need to get over 50 ng/ml to maximize the protective benefits against breast cancer. Again, it is always good to look at the data and read the paper - so see the specifics.

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Al Jalila Foundation announced that it has received a two-year Health Access Grant for $100,000 from the Medtronic Foundation.

 

The grant will fund a local research program focusing on Vitamin D deficiency across the country. The study will concentrate on early detection, evaluation, and treatment of Vitamin D deficiency. The grant will allow Al Jalila Foundation to screen thousands across the United Arab Emirates to promote early detection and prevention of the debilitating disease.