BUT is methylfolate any safer than folic acid? The both provide the same underlying nutrient. - George
One big question is whether it's the unmetabolized folic acid that's causing all of the problems, and I don't think that this question has been conclusively answered.
Not everyone metabolizes folic acid well. Methylfolate is the form your body converts folic acid to, so at least that part of the risk is retired.
There seems to be an issue in people who have
high folate but low B12:
About 23 percent of the volunteers had B12 concentrations that the researchers deemed low. Within that group, people who had the highest concentrations of folic acid were 9.6 times as likely to show signs of cognitive impairment as those with less folic acid. Surprisingly, anemia was also 3.1 times as common in the group with high concentrations of folic acid.
Among people with healthy B12 levels, however, folic acid appeared to protect against cognitive impairment, and it had no significant relationship to anemia, the researchers report in the January American Journal of Clinical Nutrition.
"We only found potential adverse effects in people who had low vitamin B12," Morris says. "Generally speaking, folate is good for cognition."
Pharmacologist A. David Smith of the University of Oxford in England estimates that 1.8 million U.S. seniors may be at risk of anemia and cognitive impairment because of folic acid fortification. Governments in Europe and the United Kingdom have not mandated fortification, though British officials are considering it.
"I'm recommending to the U.K. government that they don't go ahead with fortification," says Smith. He also suggests that another form of folic acid might be safer.
"Folic acid fortification: the good, the bad, and the puzzle of vitamin B-12" states:
1 ) Is the balance between folate and vitamin B-12 status equally as important as the absolute concentrations of these vitamins? The application of mathematical modeling may help to answer this question (18).
2 ) By what mechanisms does a high folate status in persons with a low vitamin B-12 status cause anemia and cognitive impairment?
3 ) Is unmetabolized folic acid the culprit? Data from a small number of subjects in the United States indicate that folic acid accounts for 16% of the plasma folate in persons whose total plasma folate concentration is >50 nmol/L (19). More data on the prevalence and concentrations of folic acid in the blood are needed, the factors that influence it, and the effects it has on folate one-carbon metabolism.
4 ) Given the recent findings, would it be safer to use methylfolate instead of folic acid as a supplement?
5 ) Is the imbalance between folate and vitamin B-12 associated with any other adverse effects, particularly in vulnerable sectors of the population (eg, pregnant and lactating women and infants)? A preliminary report from India suggests that such an imbalance (low vitamin B-12 and high folate status) in pregnant mothers may have adverse effects on the health of their children (20).
6 ) Is the complex relation between folate and cancer (8, 17) possibly a reflection in part of folate's interaction with vitamin B-12?
The safest conclusion would be to make sure enough B12 is received. For myself, I'm taking l-methylfolate since my homocysteine is higher than I'd like.
s&s