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> But that 5000 IU/day put me near overdose territory when I got my serum levels checked. I need to consume 4000 IU/day just to keep my serum levels acceptable
by Strom 5y ago
> But that 5000 IU/day put me near overdose territory when I got my serum levels checked.
I need to consume 4000 IU/day just to keep my serum levels acceptable. I do agree though that blood tests are necessary. When I started getting into the vitamin D supplements, I had my blood levels tested every 3 months for a few years. I started out dangerously deficient and even 8000 IU/day was barely moving the needle in the beginning. However over a longer period 8000 IU/day ended up being too much, so I cut it down to 4000 IU/day where I've been for years now.
There are a lot of factors going into this and everyone's circumstances are different. Frequent testing to verify assumptions is a must.
I spend a good amount of time outside, going running regularly, and am in decent shape. I also eat 250g of salmon weekly, which contains about 1000-2500 IU. However at the end of the day I live in the north (59 deg lat) and the sun here is of limited impact.
- hinkley 5y agoThe mammalian liver stores vitamin A and vitamin D (polar bears store so much of the former that polar bear liver will give you vitamin A poisoning, even in small quantities). If you are deficient that usually means low reserves, so some or most of what you take will go into your liver instead of your blood. Over time your serum levels climb on the same dose, which is why you have to keep testing. It’s also why therapies for vitamin D deficiency can include prescription ultra high dose pills taken once a month for a few months, rather than (or in addition to) daily supplementation.
- Scoundreller 5y agoBody fat also stores Vit D (and A, E and K), so you also need to consider how much has been deposited there and how much of one’s body fat turnsover.