I’ve blogged numerous times on the likelihood of vitamin D deficiency (sunscreen, sun-avoidance, indoor lifestyles etc.) and on the multiple benefits of ensuring vitamin D status before conception, during pregnancy and when breastfeeding. I’ve also posted the most recent dosing recommendations from researchers at GrassRootsHealth, whose work now spans more than 3 decades. So the latest report in the BMJ stating that “universal conclusions about its [vitamin D’s] benefits cannot be drawn” made me angry.
It made lots of other health professionals angry too - with assertions that this major meta-analysis was never going to show anything meaningful when “there were so many underpowered and poorly designed trials in the mix.” The identified flaws included low doses, large differences in baseline plasma concentrations and contamination with private use of vitamin D.
Here’s the word from GrassRootsHealth on the appropriate dosages (if you're supplementing) and for a continuing appropriate relationship between your skin and the sun:
Minimize UVA while allowing UVB
10-15 minutes exposure/day between 10:00 am and 2:00 pm
Expose 40 percent of skin area
Ensure it’s a clear day without pollution
If this isn’t possible, use oral supplements of D3 to achieve 40-60ng/ml (100-150nMols/L)
RULE OF THUMB: For every 100IU ingested, there is increase of 1ng/ml
ADULT DOSE: 2,000IU/day
PREGNANCY DOSE: 4,000IU/day
BREASTFEEDING DOSE: 6,000IU/day
I'm going for the appropriate sun exposure - something that feels so wonderful has to be good for you!