Right, Graham, me old pal. Sorted our little faux pas now ?
Refreshed and back to the fray -Vit D, D3 & D2. My view.
I checked your man's blog - not impressed one bit. Bit light on substance ?
Try mine, it's a bit more comprehensive so is not what you call light reading !!
http://ods.od.nih.gov/factsheets/vitamind.asp
Here is an extract about the particulars of: Dietary supplements.
In supplements and fortified foods, vitamin D is available in two forms, D2 (ergocalciferol) and D3 (cholecalciferol).
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 [11]. The two forms have traditionally been regarded as equivalent based on their ability to cure rickets, but evidence has been offered that they are metabolized differently. Vitamin D3 could be more than three times as effective as vitamin D2 in raising serum 25(OH)D concentrations and maintaining those levels for a longer time, and its metabolites have superior affinity for vitamin D-binding proteins in plasma [6,32,33]. Because metabolite receptor affinity is not a functional assessment, as the earlier results for the healing of rickets were,
further research is needed on the comparative physiological effects of both forms. Many supplements are being reformulated to contain vitamin D3 instead of vitamin D2 [33]. Both forms (as well as vitamin D in foods and from cutaneous synthesis) effectively raise serum 25(OH)D levels [6].
Whatever benefits you MAY get - do you really want a manufactured product such as this in your system ?
You can go further and look at:
ergosterol a chemical compound
a white crystalline organic solid of the molecular formula C28H44O belonging to the
steroid family. It is found only in fungi (e.g, Saccharomyces and other yeasts and Claviceps purpurea, the cause of ergot, a fungal disease of cereal grasses) and is chemically related to cholesterol.
Ergosterol is converted by ultraviolet irradiation into ergocalciferol, or vitamin D2, a nutritional factor that promotes proper bone development in humans and other mammals.
There are many more avenues I could go down - but won't bore you. I think you are one of the converted ? I still would not want to ingest any of this stuff - natural for me every time. :mrgreen:
BTW Katherine I am sure you are a wonderful cook and could rustle up a cow pie for me anytime, with a side order of eel, catfish and mushrooms rissotto. It's not my fault all the research seems to be done in the States or Canada :lol:
Dave - I think you have got it in one. So perceptive - why didn't I think of that. Would have saved so much time.
Ken. (not so tired now)
I rest my case ?