Dear all:

With a PhD in nutrition and epidemiology, I have to say the cavalier manner
in which people "prescribe" nutritional supplements in huge overdoses
scares me.  I have worked on micronutrient programs and studied particular
nutrients in depth and we are a long way away from having adequate
knowledge to determine the complex biochemical interactions in the body
when we start increasing dosages beyond that which we can cram into our
bodies from foods.  The more I study nutrition, the less I really feel we
know. We have just scratched the surface on how foods interact in our
bodies. Megadoses should be considered "drugs" or "medications" and treated
with the same respect that all drugs or medications are treated.  Vitamins,
especially fat soluble vitamins such as A, D & E, can be toxic.

That having been said, there has been a considerable amount of research
done on vitamin A and beta-carotene supplements in developing countries
because vitamin A deficiency is a huge problem that causes an increase of
about 34% in the death rates of children in areas of deficiency AND more
recent studies have suggested cause an increase in post partum death rates
of about 50% in Nepal (and probably other areas that have similar levels fo
deficiency).  In the face of such an overwhelming impact on mortality and
the fact that many of the beta-carotene and retinol-rich foods are
unavailable or unaffordably, retinol and beta-carotene supplements have
been used on a large scale.

Yes, doses of RETINOL of 5000-10,000 IU are most decidedly not safe during
pregnancy.  The reason is that retinol is teratogenic; it can cause severe
congenital anomalies.  Beta-carotene is NOT the same compound as retinol -
it is essentially two molecules of retinol stuck together and the body must
cleave the two molecules so it will be absorbed.  I'm not sure how much
protection the body has with beta-carotene absorption in high levels.  I do
know that you can get caretenosis (orange skin) with repeated doses at
those levels.

A SINGLE dose of retinol has been used among postpartum women in areas of
vitamin A deficiency.  Mothers are given A SINGLE DOSE of 200,000 IU
retinol within  8 weeks after delivery.  This has been shown in huge
population trials to be safe among DEFICIENT POPULATIONS.  This amount of
retinol stays in the liver for six months.

If this mother has been taking megadoses of retinol or beta-carotene
already or if she has a good diet, her liver may already be saturated. I
see absolutely no reason to put her own health at risk.

There have also been trials of retinol and beta-carotene in postpartum
women in Nepal.  If I recall they may have used weekly dosages that were
well within the safe range for pregnancy.  The low dosages of beta-carotene
reduced maternal mortality by slightly over 50% and the low dosages of
retinol reduced maternal mortality by slightly more than 40%.  This was in
a severely vitamin A deficiency population of women.  These women would
have had minimal stores of retinol in their liver.

I see absolutely no reason to use megadoses that would put this woman's
health at risk.  A better approach would be to eat reasonable amounts of
beta-carotene rich foods on a daily basis.

I'll be happy to look up any additional information needed since I have a
stack of books on vitamin A.

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