Calculating my vitamin D intake sounds difficult and unreliable. Is there any way to measure my vitamin D levels by examining my body?
I recall reading about a researcher in Boston (I think) who said after about mid October you could be sprawled buck naked on a rooftop all day and not get enough vitamin D from (brief winter) sun exposure.
http://www.cbc.ca/news/health/story/2008/05/16/f-health-vita...