Re: Vitamin D done right. Anyone???

More info on D:

Vitamin D is available in two forms, D2 (ergocalciferol) and D3 (cholecalciferol) that differ chemically only in their side-chain structure. Vitamin D2 is manufactured by the UV irradiation of ergosterol in yeast, and vitamin D3 is manufactured by the irradiation of 7-dehydrocholesterol from lanolin and the chemical conversion of cholesterol ….. at high doses vitamin D2 is less potent….

….In contrast to 25(OH)D, circulating 1,25(OH)2D is generally not a good indicator of vitamin D status because it has a short half-life of 15 hours and serum concentrations are closely regulated by parathyroid hormone, calcium, and phosphate. …..

…..An additional complication in assessing vitamin D status is in the actual measurement of serum 25(OH) D concentrations. Considerable variability exists among the various assays available (the two most common methods being antibody based and liquid chromatography based) and among laboratories that conduct the analyses. This means that compared with the actual concentration of 25(OH) D in a sample of blood serum, a falsely low or falsely high value may be obtained depending on the assay or laboratory used….

http://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

9 things that can undermine your vitamin D level

E.g. colour and temperature of skin, weight, liver, kidney, gut health

http://www.health.harvard.edu/healthbeat/9-things-that-can-undermine-your-vit...

Benefits of vitamin D are almost entirely negated in those with the highest vitamin A (retinol) intake

“The crux of the problem is that a form of vitamin A, retinoic acid, weakly activates the vitamin D response element on the gene and perhaps blocks vitamin D's more robust activation. In fact, the authors of a 1993 study state "there is a profound inhibition of vitamin D-activated...gene expression by retinoic acid."

http://articles.mercola.com/sites/articles/archive/2010/03/16/warning-new-pro...

And to confuse the issue further, Shane Ellison’s view on Vit D:

http://thepeopleschemist.com/the-vitamin-d-scam/

Last, but not least…..

Did You Know Vitamin D Absorption Could be Blocked by Stress?

http://naturalsociety.com/stress-blocking-vitamin-d-absorption/

Hope this helps