acne, vitamin A and its analogs
Recently someone asked about vitamin A and it suse in controlling acne.
Coincidentally it came to my attention that hospitals in New Zealand
use a vitamin A analog to treat acne.
My question, why can't the doctors prescribe straight E (or the stable
form or carotene which the body could split to provide on demand Vit E).
I understand that the drug companies charge about US$ 600/anum for their
form of vitamin E whereas codliver oil would cost much less than one
tenth of this even in mega doses. Any clues ?
-We must be observing some sort of "vowel shift" in New Zealand
where the letter A goes to E. How is it that you go from talking
about Vitamin A in one sentence to Vitamin E in the next? As it
is, your statement is simply bizarre. If we replace "Vitamin E"
throughout with "Vitamin A" it simply becomes incorrect.
The topical drug tretinoin and the oral drug isotretinoin are forms
of retinoic acid. Vitamin A is retinol, the alcohol. All three of
the drugs, while superficially similar in chemical composition, are
different enough that they have different toxicities and pharmacologies.
Vitamin A (retinol), which is found in cod liver oil, among other sources,
is completely ineffective in treating acne. Tretinoin and isotretinoin
do not substitute for vitamin A in human nutrition. They're completely
different.
-Consider yourself corrected.
People with acne do not have a vitamin A deficiency. Large doses of
the vitamin (retinol) do not influence the skin condition and are toxic.
That's about as good a reason as any not to administer it--toxic and
useless. Contrast this with isotretinoin (Accutane) which is toxic
(usually manageably so) yet has an impressive and long-lasting effect
on severe acne which hasn't responded to other measures.
Bacterial infection is an important component of acne, but it seems to be
secondary to a more basic process involving the sebaceous glands. Isotretinoin
reduces their size and prevents them from closing and forming a cyst in which
lipophilic bacteria can breed. Isotretinoin also seems to have an anti-
inflammatory action; it reduces the release of inflammatory agents by
white blood cells in the vicinity of the pores.