Vitamin A

A major new study of Vitamin A has found that doses only slightly above the maximum recommended levels during the early stages of pregnancy significantly increase the risk of birth defects. The results prompted researchers to recommend that women of childbearing age consume Vitamin A primarily from their diet, along with modest levels in multivitamin supplements.

HIV-positive women who are breastfeeding should not be given vitamin A supplements because it increases the risk of transmitting the AIDS virus to their infants, researchers said Thursday. Mother-to-child transmission of HIV has been largely controlled in the United States and other developed countries through the use of antiretroviral drugs, but is a major problem in the developing world. In 2008, there were 430,000 new HIV infections in infants, most of them in sub-Saharan Africa, and breast feeding accounted for more than 95% of them.

A derivative of vitamin A reverses the effects of emphysema in laboratory rats, U.S. scientists reported. Rats with emphysema-like lung afflictions were given the derivative, and their lungs returned to normal, researchers said in the journal Nature Medicine. Dr. Claude Lenfant of the National Heart, Lung and Blood Institute said this might lead to treatments for emphysema and other lung ailments.

Researchers have reported the development of a new combination drug that will allow patients to take high doses of the cholesterol-lowering vitamin niacin without a painful and embarrassing side effect known as flushing. Niacin has been shown to be an effective agent for lowering bad cholesterol, increasing good cholesterol and reducing cardiovascular risk, but three-quarters of those who take it discontinue use within a year because of flushing, which is characterized by a severe reddening of the skin.

Tales of Vitamin A toxicity are often bizarre, centering on Arctic explorers eating huge amounts of polar bear liver or fitness fanatics gobbling handfuls of vitamin supplements. But Americans should be aware that more subtle overloads of Vitamin A might pose some serious health risks, particularly to pregnant women, children and the elderly, federal nutrition experts say.

In a development with potential implications for millions of children worldwide, researchers have found that a small weekly dose of Vitamin A can markedly reduce mortality among malnourished preschool-age children. The study of 15,419 children from southern India, being reported in today's issue of the New England Journal of Medicine, may help to settle a longstanding scientific controversy about the health benefits of Vitamin A supplements for children with inadequate diets.

Seasoning rice with daffodil and bacteria genes, scientists have boosted the vitamin A content of the developing world's most widely consumed grain in the hope of ending a common dietary deficiency that kills 1 million poor children every year, according to research made public Thursday.

Too much vitamin A may increase the risk of hip fractures in older women, according to a study researchers say suggests the need to reevaluate the levels in supplements and fortified food. Vitamin A is important for such things as healthy skin and hair and bone growth. But in the study published in Wednesday's Journal of the American Medical Assn.

Vitamin A used in combination with a chemotherapy drug can prolong the lives of patients suffering from a type of leukemia that most often strikes middle-aged adults, according to a new study by UC Irvine cancer researchers. In adult patients with chronic myelogenous leukemia, the therapy could delay by as much as eight months the onset of the disease's acute stage, when patients deteriorate rapidly, according to Dr. Frank L. Meyskens Jr.

Last year, when Dr. Gloria De Carlo Massaro published a study suggesting that vitamin A could be used to grow lung tissue in newborn rats, phones rang off the hook from desperate patients seeking a cure for emphysema. Sorry, she said, human studies are years away, and tinkering with this particular vitamin could be dangerous. She and her colleagues at the Georgetown University School of Medicine have spent the last year doing studies on adult rats with emphysema-like damage in their lungs.

A small study has shown it may be possible to reverse somewhat the wrinkling of old age. The research suggests that topical application of retinol, a form of vitamin A, could make older people less prone to skin ulcerations and poor healing of wounds. Three dozen white people -- average age, 87 -- had a skin moisturizer laced with retinol applied to one of their inner arms a couple of times a week for six months; a placebo was applied to the other arm.

Too much vitamin A may increase the risk of hip fractures in older women, according to a study researchers say suggests the need to reevaluate the levels in supplements and fortified food. Vitamin A is important for such things as healthy skin and hair and bone growth. But in the study published in Wednesday's Journal of the American Medical Assn.

Metabolife International said Tuesday it is voluntarily recalling its nationally distributed energy bars that could contain toxic levels of vitamin A. The recall involves 1.5 million Metabolife Diet & Energy Bars made Dec. 25 through May 4. San Diego-based Metabolife said the excessive amounts of vitamin A were discovered during recent routine sampling. The company reported its tests to the contract manufacturer, which confirmed the results, and then contacted the Food and Drug Administration.

Your mother always told you to eat your carrots--they were good for your eyes. Now she may start nagging you to eat just a few more. A panel of researchers from the Institute of Medicine said last week that a new review of recent research shows that dark vegetables--such as carrots, sweet potatoes and broccoli--provide the body with only half as much vitamin A as previously thought--meaning consumers must be sure to eat enough of these, especially if they shun meat and fortified milk.

Monsanto's pledge to allow the developers of a genetically modified rice to use any of the company's patented technology for free could help convince the public that genetically modified foods can offer tangible benefits to consumers, analysts say, without costing the company a dime in lost sales. Monsanto, a division of Pharmacia Corp.

Seasoning rice with daffodil and bacteria genes, scientists have boosted the vitamin A content of the developing world's most widely consumed grain in the hope of ending a common dietary deficiency that kills 1 million poor children every year, according to research made public Thursday.

Large daily doses of Vitamin A can slow the slide toward blindness for patients with retinitis pigmentosa and may save years of eyesight for 100,000 Americans with the inherited affliction, a new study indicates. The same study also showed that large supplemental doses of Vitamin E actually accelerate the disease, said Dr. Eliot L. Berson, a Harvard Medical School researcher.

High doses of Vitamin A dramatically reduced the duration of measles and cut the death rate by more than half in a group of children suffering from a severe form of the highly contagious disease, South African researchers said last week. Measles kills about 2 million children a year, especially in developing countries, despite vaccines that could prevent the viral disease.

Last year, when Dr. Gloria De Carlo Massaro published a study suggesting that vitamin A could be used to grow lung tissue in newborn rats, phones rang off the hook from desperate patients seeking a cure for emphysema. Sorry, she said, human studies are years away, and tinkering with this particular vitamin could be dangerous. She and her colleagues at the Georgetown University School of Medicine have spent the last year doing studies on adult rats with emphysema-like damage in their lungs.

A derivative of vitamin A reverses the effects of emphysema in laboratory rats, U.S. scientists reported. Rats with emphysema-like lung afflictions were given the derivative, and their lungs returned to normal, researchers said in the journal Nature Medicine. Dr. Claude Lenfant of the National Heart, Lung and Blood Institute said this might lead to treatments for emphysema and other lung ailments.