Hi. I'm hypothyroid so have been on Calcium w/D supplement for years. Started researching more about vitamin D3 (aka Cholecalciferol) after my MS dx because there is a suspected connection.

I started supplementing with vitamin D3 and as indicated above in a post above, it sure seems that in the general population, a deficiency is more common and goes undetected. I know that there has at least been some discussion about the RDA being officially raised.

When dosing with vitamin D3, the amount that most consistently comes up is 4,000 IUs daily although in the summer months (or if you live in a sunny climate year round) this should be reduced to 3,000. I have also read accounts from people who are taking 50,000 IUs (!) once a week on advice of their doctors.

Too much vitamin D can be toxic so my endocrinologist tested my level and liver function last week. I asked him about that 50,000 IU megadose I've read about some people taking and he said that they're finding that if it's spaced out like that (once a week) there doesn't seem to be the same problems with toxicity.

If you are supplementing, please let your doctor know so that they can check your levels and liver function. Vitamin D3 is really interesting because it actually functions in the body like a hormone. I use Jarrow -- they're little gelcaps and pretty inexpensive.

I'm happy to be here -- I am so impressed by what I've read! You guys sure know a lot and it's a breath of fresh air for me! Hope you don't mind me chiming in.