hi indianbackground
D3 , ( cholecalciferol ) is the mammalian form of vitamin D ,
D2 ( ergocalciferol ) is made from plants , it has a different chemical structure to the mammalian form.
It is better to use D3 and not D2 . Recent research has shown this to be the case. Even though D2 does have some activity , for example against rickets, you would nowadays be advised by vitamin D researchers to use Vit D3.
The dose that you take entirely depends upon what you are trying to do, vis-a-vis your vitamin D blood levels.
IF you take a daily dose of 1000 IU ( 25mcg ) continuously, i.e.daily, then you can expect your blood level to rise by 25 , from your unsupplemented level. That is an average response. We all do vary.
It is better to take vitamin D3 as close to daily as possible. Every other day is not bad, one a week is not so good , and monthly is not good at all. The reason for this is that VitD3 supplement ( cholecalciferol) is quickly converted by your liver into calcidiol in the blood. However VitD3 (cholecalciferol) is used by your cells, it is important that it is available when a cell needs to pick it up from the intercellular fluid. This is an autocrine response, the cell can convert VitD3 to vitD hormone within the cell and so enable itself to read/transcribe/ regulate gene function. Almost every cell in your body has this capability. Heart,brain,skin, lungs,pancreas,muscle etc etc. So , you need vitamin D3 (cholecalciferol ) available to all cells , all the time. It is this compound which is transferred in mothers milk to baby, and NOT calcidiol . This means that mothers should have substantial doses of vitamin D3 IF they exclusively breastfeed. OR else the baby should receive supplement drops approx 350 to 400 IU daily as recommended by the NHS. <strong>*Note</strong>* Formula milk does contain the vitd (supplement) required. Cows milk does not.
Your current dosage level, i.e. 350 IU per day on average , will raise your blood level of calcidiol ( i.e.25hydroxyD3 ) by about 8 from its unsupplemented level. That is quite a small change actually.
Many people nowadays will take 1000 - 3000 IU daily, They see the importance of having blood levels of at least 75. Here in the UK, ( I assume you are in the UK ) we are very likely to be below those levels , the sun is weak, and we cannot make vitamin D in the skin from mid - Oct to mid-April. The more pigmented the skin , the less able the skin is to make Vitamin D3 . Pigmentation acts as a sunscreen.
Vitamin D is the cheapest vitamin to produce. you should be able to find a whole years supply of D3 , online , say Amazon, or others, for around £12 to £15 . A capsule containing oil ( preferably olive oil ) and vitD3 , will probably be the easiest to assimilate.
Hope this is helpful.
If you need any more info ... please get back to me
I have posted quite a bit here on Mumsnet re: Vit D.
Best of luck
BTBH.
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