Vitamin D dosage and body fat page

[racingsnake]

I have been taking vitamin D for some years and keep an eye on the various opinions on how much to take. I've seen 10,000 iu per day, 100iu / 25lb body weight and so on.

But I have always found that I get pretty high Vit D test readings from relatively low dosages - 2000-4000 iu per day, so I've been a little careful on how much I take, and a little scpetical of the higher dosage recommendations.

Then something yesterday gave me a possible a-ha moment. I was at the gym taking a pal through a workout - he's losing weight by going Primal. The gym instructor got out the body composition machine afterwards so we could monitor his fat loss. He came in at 25%. Then the guy stuck me on it as a comparison and I came in at 3.5% (!)

The machine tells me that he therefore has 3 st 7 lb of fat, and I have a measly 5.4 lb. That's, what, 7-8 times as much fat?

I know this is probably too low, and I'm working on it (watch out sweet potatoes, here I come!), but it made me think about vit D dosage.

Seeing as Vitamin D is a fat-soluble vitamin, then does it follow that those with more body fat need more vitamin D to reach a certain tissue concentration?

This would explain why I, with my stupidly low body fat, get high vit D test readings on relatively low doses.

Hmmm... anyone care to stroke their chin over this one?

[ericfoster3]

I think it's pretty well known that the fatter you are, the more Vitamin D you require...

also, the older you are.
and if you have darker skin.
and you live in a northern latitude.

There are even more factors. I don't remember them all.

[skyvue]

I had my first real physical 4 months ago (42) and the doctor put me on a low dosage of blood pressure medicine (which did not surprise me) but also put me on prescription Vitamin D. It was a 10,000 ui pill but I was only supposed to take it twice per week. I just went back and had my blood retested and my Vitamin D levels were back to normal levels. He suggested I now go to an over the counter solution for the Vitamin D and told me to go with the 1,000 ui dosage each day. At least according to him, there is no need for higher dosages.

Yes, the fatter you are the more Vitamin D you need. Recently heard this on the Dr. Oz show and was also confirmed by my doctor.

[Suse]

I think you'll find on Cillakats vit d thread she recommends 1000iu per 25lbs of body weight.

[racingsnake]

OK, so it seems I'm a bit behind the times here! Nice to have an explanation for why my levels were so high on a relatively moderate dose though, and perhaps a warning for other skinny types to watch their dosage rather than following a 'one size fits all' prescription.

[animalcule]

Great posting for me, thank you. I am just starting to supp. again now that I'm not getting so much sunlight on my body. At 100 lbs and 'athletic' BF% for a woman I had better not overdo it.

[avocado]

I think Cillakat is always pretty careful to say that 1000 IU/lb body weight is only a safe place to start until you get tested in 3 months, not as a substitute for getting tested.

[MalPaz]

i dunno if this is relavant but the more sun/vita D i get the better i handle carbs

[racingsnake]

Testing is clearly vital, as you say Avocado

[Grizz]

Here is an alternative opinion.

A friend is taking 20,000 IU Vit D3 daily. His doctor told him that he could not overdose on Vit D3, so advised taking a large dosage every day to be certain of getting enough. He has been doing this for 2 years now, and has not noticed any ill effects. He laughed at me when I suggested he get his blood tested for Vit-D levels.

Could this be TRUE? Off to my favorite authority: Wicki Says:

"In healthy adults, sustained intake of 1250 micrograms/day (50,000 IU) can produce overt toxicity after several months"
http://en.wikipedia.org/wiki/Vitamin...e_by_ingestion

Another series of studies concludes similar results:

They go on to state, "...cases of vitamin D toxicity with hypercalcemia, for which the 25(OH)D concentration and vitamin D dose are known, all involve intake of (greater than or equal to) 40,000 IU/d."

That's Forty Thousand IU's per day to produce a true Overdose on Vitamin D with the required Elevated Calcium levels to go along with it! That's NOT what doctors and governments are telling us, so doctors give us inadequate amounts of Vitamin D in order to prevent a nearly fictitious possibility of overdose on Vitamin D!

Another study gave pregnant women 100,000 IU's per day for the entire length of their pregnancy. The study concluded,"Thus, there is no evidence in humans that even a 100,000 IU/d dose of vitamin D for extended periods during pregnancy results in any harmful effects."
http://www.easy-immune-health.com/Ov...Vitamin-D.html

Bottom line:
So it appears that my friend is no where near overdosing at only 20,000 IU per day, and his doctor is correct.
No doubt there are conflicting studies out there. Aren't there always? Nutrition is NOT an exact science!

Best of health to all,
Grizz