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Join Dr. McDougall along with fellow McDougallers in lively discussions and share your opinions.
Something like this?ETeSelle wrote:Proof of that???
Note, some have low D and some are fine. Blood testing is the only way to know for any given individual.The Journal of Clinical Endocrinology & Metabolism, doi:10.1210/jc.2006-2250
The Journal of Clinical Endocrinology & Metabolism Vol. 92, No. 6 2130-2135
Copyright Â© 2007 by The Endocrine Society
Low Vitamin D Status despite Abundant Sun Exposure
N. Binkley, R. Novotny, D. Krueger, T. Kawahara, Y. G. Daida, G. Lensmeyer, B. W. Hollis and M. K. Drezner
Context: Lack of sun exposure is widely accepted as the primary cause of epidemic low vitamin D status worldwide. However, some individuals with seemingly adequate UV exposure have been reported to have low serum 25-hydroxyvitamin D [25(OH)D] concentration, results that might have been confounded by imprecision of the assays used.
Objective: The aim was to document the 25(OH)D status of healthy individuals with habitually high sun exposure.
Setting: This study was conducted in a convenience sample of adults in Honolulu, Hawaii (latitude 21Â°).
Participants: The study population consisted of 93 adults (30 women and 63 men) with a mean (SEM) age and body mass index of 24.0 yr (0.7) and 23.6 kg/m2 (0.4), respectively. Their self-reported sun exposure was 28.9 (1.5) h/wk, yielding a calculated sun exposure index of 11.1 (0.7).
Main Outcome Measures: Serum 25(OH)D concentration was measured using a precise HPLC assay. Low vitamin D status was defined as a circulating 25(OH)D concentration less than 30 ng/ml.
Results: Mean serum 25(OH)D concentration was 31.6 ng/ml. Using a cutpoint of 30 ng/ml, 51% of this population had low vitamin D status. The highest 25(OH)D concentration was 62 ng/ml.
Conclusions: These data suggest that variable responsiveness to UVB radiation is evident among individuals, causing some to have low vitamin D status despite abundant sun exposure. In addition, because the maximal 25(OH)D concentration produced by natural UV exposure appears to be approximately 60 ng/ml, it seems prudent to use this value as an upper limit when prescribing vitamin D supplementation.
JeffN wrote:Individuals can always find a study or two to support a position. This is why a consensus opinion by an expert panel is so important. No one or two study can or will supersede the consensus especially when the consensus has already considered these exact individual studies I'm their report.
Chimichanga wrote:Vitamin D Levels Linked With Health of Blood Vessels
http://www.sciencedaily.com/releases/20 ... 205232.htm
NevadaSmith wrote: I don't recall what they say here?
Having lived in that area for 10 years or so, that seems like a non-sequitor to me! Fog, fog, and more fog, cold and windy... plus pretty far north...But I am going to try to get it from sunlight, as I do live in San Francisco after all.
GeoffreyLevens wrote:Having lived in that area for 10 years or so, that seems like a non-sequitor to me!But I am going to try to get it from sunlight, as I do live in San Francisco after all.