Plasma calcidiol, season, and serum parathyroid hormone concentrations in healthy elderly men and women.
Dawson-Hughes B, Harris SS, Dallal GE.
Am J Clin Nutr. 1997 Jan;65(1):67-71.
PMID: 8988915
Plasma calcidiol and serum PTH concentrations were inversely related, with PTH rising slowly as calcidiol concentrations declined below 110 nmol/L (95 CI: 60, 168 nmol/L). More than 90% of the men and women had calcidiol concentrations below this value in the wintertime. The high prevalence of lower wintertime calcidiol values may increase risk of bone loss in elderly men and women.
"Maybe vitamin D isn't the answer after all.
Not only does the above statement ring true, it's also the title of a recent post on "Dr. Len's Cancer Blog" - a website written by Dr. Len Lichtenfeld, Deputy Chief Medical Officer for the national office of the American Cancer Society, in order to facilitate communication with the public on important issues related to cancer. "