Cold and Flu Season is Approaching (Part 2)
In our last post about cold and flu season approaching, we reviewed similarities between months with the highest flu activity and vitamin D levels in a general population, as well as the risk reduction...
Vitamin D levels and supplemental intake among Canadian GrassrootsHealth participants
As we saw in an earlier post of this series, GrassrootsHealth participants reside in 55 countries worldwide with over 1,000 residing in Canada (the country with the largest number of participants after the United...
The Effectiveness of Vitamin D Sprays
One of the questions we have received from our D*action participants is “Are vitamin D sprays as effective as other forms taken by mouth, such as pills and capsules?” This is a concern especially...
Vitamin D and Prostate Cancer
Did you know that one out of every seven men will get prostate cancer in their lifetime? This is much too high. Since it is prostate cancer awareness month, we wanted to take the...
Average Vitamin D Levels by Location among GrassrootsHealth Participants
As we saw in the first of this series, GrassrootsHealth participants reside in 55 countries worldwide. Today, we’ll look at how vitamin D levels vary by location. Vitamin D levels by country for GrassrootsHealth...
Is Your Vitamin D Level Too High?
Key Points The GrassrootsHealth scientists’ consensus recommended range of vitamin D for general health is 40-60 ng/ml (100-150 nmol/L), based on overwhelming evidence about the association between vitamin D and many diseases; there is...
Hypertension risk lower with higher vitamin D status
Studies have shown that low vitamin D levels are a risk factor for cardiovascular disease. Using the data you provided for the GrassrootsHealth Nutrient Research Institute study, we assessed the association between vitamin D...
Tanning as a Source of Vitamin D
Two different research groups conclude the US RDA is off by an order of magnitude GrassrootsHealth scientists and staff have published a research letter, citing the D*action data, calling for the Institute of Medicine...
Vitamin D Testing Reduces Healthcare Costs
Researchers in Tennessee believed that vitamin D deficiency could lead to chronic ailments, which in turn increases health care costs. The Veterans Administration is interested not only in the health of their veterans, but...
Effect of BMI on Vitamin D Dose-Response
Evidence shows that vitamin D levels are affected by obesity. Using the data you provided for the GrassrootsHealth study, we assessed the effect of BMI on vitamin D dose-response. We found that with increasing...