& Joannie Dobbs Wednesday,
April 15, 1998
Taking folate supplements not for
The more we learn about nutrients and how they function to keep the body healthy, the more complicated seemingly simple public health recommendations can get. In a previous column (March 18), we discussed the factors that make it difficult to provide “one-size-fits-all” recommendations for the amount of salt and sodium in the diet. This column addresses a somewhat similar issue related to two B-vitamins, folate and vitamin B-12. And by the way, folate, folic acid, and folacin are all forms of the same vitamin.
Folate has been in the news lately for a few reasons. First, high blood levels of a compound called homocysteine have been associated with an increased risk of heart disease. A diet with adequate folate helps normalize homocysteine levels and possibly decrease the risk of heart disease.
Second, a diet rich in folate (400 micrograms per day), at conception and during pregnancy has been shown to decrease the incidence of serious spinal cord defects in newborn infants by 75 percent.
Foods highest in folate include fortified cereals, liver, nuts and seeds, green vegetables and seaweeds such as wakame, and some fruits such as oranges. Since Americans are not known for eating large amounts of these foods, as of January this year all enriched flour and flour products will be fortified with folic acid. This alone will increase dietary folate for many.
However, just last week, the National Academy of Sciences provided new recommended dietary allowances for folate that are 50 to 100 percent higher than past recommendations for most age-groups.
So, should we all run out and start taking folate supplements? The short answer is a qualified yes and no; yes for some people, such as many females of childbearing age; and no for others, such as those who are at risk for Vitamin B-12 deficiency – some elderly, those taking ulcer or heartburn medications over long periods, those with HIV or AIDS and strict vegetarians (vegans).
For some functions, Vitamin B-12 and folate function as part of a metabolic team. For other functions, they work separately. A deficiency of vitamin B12 can cause depression, dementia and irreversible physical damage to the nervous system, including decreased sensations in the hands and feet. Finally, it can bring about irreversible short-term memory loss.
A potential problem with folate supplementation is that large amounts of folic acid prevent red blood cells from appearing abnormal. This can mask the usual diagnostic indicator of B-12 deficiency until the nervous system is irreversibly damaged. Reaching the final stages of vitamin B-12 deficiency generally takes five to eight years.
So what can someone do to get enough folate without having the potential negative side effects of masking a B12 deficiency? If you fall into one of the risks groups, make sure you include good B-12 sources in your diet or take a B-12 supplement. Good sources of vitamin B-12 are liver, milk, cheese, yogurt, eggs or animal meats. Today many vegan foods, such as vegan burgers and soy milk, have added B-12. Read food labels to determine if your brand of “vegan” product is fortified.
Make sure that your physician knows if you are having any B-12 deficiency symptoms or are taking any prescribed or over-the-counter medications that decrease stomach acids. Decreased stomach acids generally mean decreased absorption of the B-12 in foods. Monthly injections of the vitamin may be required due to stomach problems in some people.
Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S.
are nutritionists in the Department of Human Nutrition, Food and Animal Sciences,
College of Tropical Agriculture and Human Resources, UH-Manoa.
Dr. Dobbs also works with the University Health Service
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