howard@metheus.UUCP (Howard A. Landman) (03/05/84)
Since my wife is pregnant, I have spent some time trying to assure that she gets a decent diet. One of the problems I have had is that I would like her to be getting about 4 mg of folic acid per day, but it is apparently illegal to use more than .8 mg (800 mcg) in any non-prescription pill. The only justification I have ever seen for this was a vague reference in one book to folic acid "masking" pernicious anemia (B-12 deficiency). So, two questions: (1) Is there a law/ruling that limits the maximum amount of folic acid in non-prescription medications to 800 mcg? Who issued this? When? Is there a similar limit in other civilized countries than the U.S.? (2) Even if folic acid masked B-12 deficiency, wouldn't it be safe to allow large amounts of folic acid in a multiple vitamin which included reasonable amounts of B-12? My interim solution is to give her several 800 mcg folic acid pills in addition to the C, multiple, B, E, etc. that she was already taking; but this is not very cost-effective. Howard A. Landman ogcvax!metheus!howard
sdyer@bbncca.ARPA (Steve Dyer) (03/06/84)
Yes, folic acid can "mask" development of B-12 deficiency, and as such is limited to 0.4mg per over-the-counter supplement. This restriction protects those people who will develop pernicious anemia, a condition where B-12 cannot be absorbed by the digestive system even in VERY large doses. This explains the FDA's restriction regardless of the amount of B-12 in the supplement. B-12 deficiency develops very slowly and such a person who had the habit of taking milligram quantities of folic acid would probably end up with severe CNS damage by the time the deficiency had advanced sufficiently to break through the masking effect. Doctors know the importance of folic acid supplementation during pregnancy. Why doesn't your wife get a prescription for the vitamin (or a prescription-only multi-vitamic) instead of trying to "mix-and-match" with over-the-counter preparations? -- /Steve Dyer {decvax,linus,ima}!bbncca!sdyer sdyer@bbncca.ARPA
dave@utcsrgv.UUCP (Dave Sherman) (03/06/84)
My wife has been taking a prenatal supplement called "Orifer-F" throughout her pregnancy. It seems that all the other women in our prenatal class have been taking it also. It contains folic acid among other things. Dave Sherman Toronto -- {allegra,cornell,decvax,ihnp4,linus,utzoo}!utcsrgv!dave
dave@utcsrgv.UUCP (Dave Sherman) (03/07/84)
Canada obviously has no such restriction on folic acid intake. I just checked my wife's Orifer-F, which she (and most other pregnant women here, it seems) has been taking every day for the last 7 months or so, and it contains 5 mg of folic acid per tablet. (It also contains lots of other vitamins and whatnot.) Dave Sherman Toronto -- {allegra,cornell,decvax,ihnp4,linus,utzoo}!utcsrgv!dave
ix21@sdccs6.UUCP (03/08/84)
Metheus!howard asks if there is any justification to FDA's recommendation to limit the amount of folic acid in oral tablets to 1 mg. The side effects to folic acid toxicity are not limited to masking the diagnosis of pernecious anemia. Other side-effects are attributed to high levels of folic acid including the possibility of seizures. {Reynolds, E. H. Neurological aspects of folate and vitamin B12 metabolism. Clinical Haematology. 1976, 5, 661-696. In addition there is additional evidence that excess vitamins administered to pregnant females may result in the child having an increase need for vitamins. -- David Whiteman sdcsvax!sdccs6!whiteman UCSD Medical School, La Jolla CA {insert boring .signature file here}
howard@metheus.UUCP (Howard A. Landman) (03/16/84)
Thanks for the several replies I have gotten. I have also done some further research, and will try to summarize the results here. The FDA is indeed the agency limiting folic acid. All limits are expressed in terms of "folacin", which is an imaginary compound having exactly the potency of pure folic acid. There are compounds other than folic acid which have some potency to replace it, just as there are multiple forms of "niacin". The principal reason for the limitation was the masking of pernicious anemia mentioned earlier. The specific symptom masked is megaloblasty, i.e., having abnormally large red blood cells. There is a special reaction that takes place with red blood cells leading to the death of their nucleus, which is necessary for them to mature into normal red blood cells. This reaction involves methylation, and requires B-12, folic acid, and methionine (an amino acid with a methyl group attached to a sulfur atom). If a developing red blood cell fails to undergo this reaction, it becomes (stays?) abnormally large and also is less able to perform its duties carrying oxygen. One of the first symptoms of B-12 deficiency is megaloblasty, and it is easy to detect just by looking at a drop of blood under a microscope. For this reason B-12 deficiency is sometimes also known as "megaloblastic anemia". Large amounts of folic acid prevent the megaloblasty (but not the other effects of B-12 deficiency!), and hence make B-12 deficiency harder to detect. Thus the FDA did have a difficult decision to make, and they effectively decided to limit access to large amounts of folic acid by treating it as a prescription drug except in small doses. The difficulty with this is that it makes buying folic acid much more expensive since you have to pay the costs of fillers, pill-pressing, packaging, etc. A pill with nothing (effective) in it except 800 ug of folic acid costs almost as much as a complete B-complex pill INCLUDING the same 800 ug of folic acid. So while the limit protects the population-at-large from doing something potentially foolish, it also makes life marginally more expensive for anyone who understands the rudiments of human nutrition and tries to act on that knowledge. More than one person strongly suggested I have my wife see a doctor. Thanks, but she has been seeing one since three months before we started trying to get pregnant, seven months before we succeeded. The vitamins he tried to sell us, sold "through doctors only", were reasonably good but VERY expensive. And they didn't have as much folic acid as I wanted for myself, let alone for a pregnant or lactating woman. I appreciate the concern, but as a former biochemisty major who has also taken a quarter course in Nutritional Science I feel I am better equipped to calculate optimum vitamin levels than the average MD. A cardiologist friend of mine went through six years of medical school (after four years of pre-med study at Berkeley) and in those ten years had exactly TWO HOURS of lectures on nutrition. One other item which may be of interest to the druggies on the net: it turns out that nitrous oxide (NO,laughing gas) inactivates vitamin B-12, and in fact is used in laboratories as a standard and relatively easy way of inducing B-12 deficiency. In some circles NO is a widely used intoxicant since it is legally available in the form of "whippets" (the little cartridges sold to make whipped cream). If you use NO regularly you might seriously consider taking supplements of B-12 and getting your blood checked once in a while (when you see your doctor ASK THEM TO CHECK FOR THIS). And, as you can see from the above, you should not be taking large amounts of folic acid! Howard A. Landman ogcvax!metheus!howard