Jun 30, 2011

Vitamin D Deficiency

It has long been known that getting enough vitamin D is key to bone health, yet vitamin D deficiency remains a common health issue, experts say.
According to the Endocrine Society, very few foods naturally contain or are fortified with vitamin D, and sunlight is one of the best sources of the nutrient. People who don't get enough vitamin D are at risk for calcium, phosphorus and bone metabolism abnormalities, which can lead to a number of diseases, including osteoporosis. Children with a vitamin D deficiency can also develop skeletal deformities known as rickets, the experts pointed out in a society news release."
Vitamin D deficiency is very common in all age groups, and it is important that physicians and health-care providers have the best evidence-based recommendations for evaluating, treating and preventing vitamin D deficiency in patients at highest risk," Dr. Michael F. Holick, of Boston University School of Medicine, said in the news release. Holick chairs a task force that authored the society's new clinical practice guidelines published in the July issue of the Journal of Clinical Endocrinology & Metabolism. The Endocrine Society issued the guidelines in response to the possible health risks associated with vitamin D deficiency. Among the group's recommendations:People who are considered at high risk should be routinely screened for vitamin D deficiency. People who are diagnosed with a vitamin D deficiency should be treated with either a vitamin D2 or vitamin D3 supplement. To maximize bone health and muscle function, people considered at high risk for a deficiency should adhere to the following guidelines for dietary intake of vitamin D:Infants up to 12 months of age require at least 400 international units (IU) a day. Children older than 1 year and adults from 19 to 70 years old, including pregnant and lactating women, should consume at least 600 IU daily.People older than 70 years should get a minimum of 800 IU a day. The task force stressed that in order to raise the blood level of vitamin D consistently above 30 nanograms per milliliter, a significantly higher intake of vitamin D may be required. The group also noted that vitamin D screening is not necessary for people who are not considered at risk for the deficiency. And, it said there is no evidence supporting use of vitamin D supplements for benefits other than bone health.
SOURCE: The Endocrine Society, news release, June 6, 2011

Jun 26, 2011

High folate levels does not influence B12 levels

NIH study addresses concerns about high folate levels.
Increased folic acid from supplements, fortified foods not likely to affect B12 deficiency.

Taking folic acid supplements or eating fortified grain products is unlikely to worsen problems related to low levels of vitamin B12, according to researchers at the National Institutes of Health and five other institutions in the United States, Ireland and Norway.
In the United States, bread, cereal and other enriched flour products have been fortified with folic acid (the synthetic form of the vitamin folate) since 1998. Women with low levels of folate are at increased risk for conceiving a child with birth defects of the brain and spinal cord known asneural tube defects. The number of infants born with these birth defects has fallen since fortified foods were introduced.Researchers have been concerned that the level of folic acid in fortified grains — needed to reduce women’s risk for conceiving a child with a neural tube defect — might be too high for other people. These concerns stem from earlier studies that found higher rates of anemia and other blood abnormalities in people with low B12 levels who also had high folate levels. The people with low B12 and high folate levels were more likely to have anemia than did people with low B12 levels and normal folate levels.However, many of these studies were conducted in older people, a group more likely to have difficulty absorbing B12. Researchers were uncertain whether these blood abnormalities were due to the high folate levels or to medical conditions common to older people. For this reason, the NIH researchers conducted the current study in otherwise healthy younger people to determine if high folate levels alone had an influence on B12 metabolism.The body uses vitamin B12 to make red blood cells. Because they may have difficulty absorbing sufficient B12, it is recommended that adults over age 50 should take a supplement. People with low B12 levels can develop anemia, a condition in which the body does not make enough red blood cells to carry oxygen throughout the body. They may also develop numbness and tingling in the hands and feet."Our findings are reassuring for people who have low vitamin B12 levels," said first author James L. Mills, M.D., M.S., senior investigator in the Division of Epidemiology, Statistics and Prevention Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH institute that conducted the study. "We found no evidence that folate could worsen their health problems. Consuming higher amounts of folate does not seem to interfere with the body’s use of vitamin B12 in otherwise healthy individuals."
Folate is the naturally occurring form of folic acid. Leafy green vegetables, citrus fruits, and beans all are sources of the vitamin.The NIH researchers theorized that underlying medical problems among elderly participants could have affected earlier results. One such potential problem is pernicious anemia, a condition in which the body does not make enough of the protein needed to absorb B12 from the intestines. Other disorders or a history of intestinal surgery also could hinder the absorption of B12.
For their study, the researchers examined blood samples from a group of B12-deficient university students, screening the samples for conditions that could affect B12 absorption. The researchers found no increase in anemia rates or blood abnormalities in the high-folate group when compared with the low-folate group."In our study, we carefully checked for people who had intestinal surgery or disorders that disrupt the absorption of B12, to be sure that they did not bias our analysis," Dr. Mills said.Dr. Mills conducted the study in collaboration with nine researchers at the NIH’s National Human Genome Research Institute; Trinity College in Ireland; the University of California, Berkeley; the Health Research Board of Ireland; and the University of Bergen, Norway.Their findings appear in the American Journal of Clinical Nutrition.More than 2,500 university students participated in the study. They reported the amount and type of fortified foods and vitamin supplements they had consumed in the previous week and in an average month. They also provided blood samples.The researchers found that about 5 percent of the students were B12 deficient. The researchers further divided the students with low B12 into two groups: those with high blood folate levels, and those with low folate levels.To diagnose anemia, the researchers measured blood levels of the protein hemoglobin. They found that the rates of anemia did not differ significantly between the two groups. Moreover, those with high folate levels did not have higher blood concentrations of chemicals that are increased when B12 function is abnormal."High folate does not appear to increase the risk of anemia among healthy people with low B12 levels," Dr. Mills said.To reduce their risk of conceiving a child with a neural tube defect, it is recommended that all women capable of becoming pregnant consume 400 micrograms per day of synthetic folic acid (from fortified foods and/or supplements) in addition to food forms of folate from a varied diet.

Jun 20, 2011

Scientists Identify Genes Linked to Migraines

Inheriting any one of 3 gene variants raises risk for severe headaches by up to 15%, researchers say.
Researchers have identified three genes linked to migraine headache and found that people who inherit any one of these genes have a 10 to 15 percent greater risk for the condition.
Migraine headache -- an abnormality in the response of nerve cells to stimuli -- is characterized by recurring severe headaches, which often result in nausea as well as sensitivity to light and sound.In examining genetic data from more than 23,000 women, including over 5,000 migraine sufferers, the researchers found an association between the headaches and variations in three genes: TRPM8 (which plays a role in sensitivity to cold and pain), LRP1 (a gene involved in the transmission of signals between neurons) and PRDM16.
"While migraine remains incompletely understood and its underlying causes difficult to pin down, identifying these three genetic variants helps shed light on the biological roots for this common and debilitating condition," the study's lead author, Dr. Daniel Chasman, assistant professor in the preventive medicine division at Brigham and Women's Hospital and Harvard Medical School, said in a hospital news release.
One migraine expert called the findings "very exciting." "The thinking for a long time was that migraine is most commonly a multi-genetic condition with potentially many genetic variations that contribute," noted Dr. Audrey Halpern, clinical assistant professor in the department of neurology at NYU Langone Medical Center in New York City. "We clearly understand now that migraine is a condition characterized by disordered sensory processing."Although the study authors said the findings are encouraging, they noted that more research is needed to better understand exactly how each of these three genes is associated with migraine.Halpern agreed that much more study lies ahead to unravel the genetics of migraine. "This current research will help us more fully understand what happens during migraine, but there is also much more to learn," she said. "We've always known it's a genetic condition -- but the last 10 years we've learned it's a neurological condition. This study brings those two ideas together."
The report is published in the June 12 online edition of the journal Nature Genetics.
SOURCES: Audrey Halpern, M.D., clinical assistant professor, department of neurology, NYU Langone Medical Center, New York City; Brigham and Women's Hospital.

Jun 14, 2011


(Reuters Health) - Women with heart disease who down a few cups of coffee each day tend to live as long as those who avoid the beverage, a large study finds.
The results was reported in the American Journal of Clinical Nutrition. In theory, coffee could be problematic because it has caffeine and other compounds that can raise blood pressure or have other negative effects on the cardiovascular system. But some studies have found that coffee drinkers have no increased risk of a second heart attack or premature death. A few others have even hinted at protective effects from coffee.In this study, which followed nearly 12,000 U.S. nurses with a history of heart disease or stroke, those who regularly drank caffeinated coffee were no more likely to die than non-coffee-drinkers during the study period - which for some was more than 20 years.
Researchers found no link between a woman's coffee intake and her risk of death from heart attack, stroke or any other cause. And that was true even of women who downed four or more cups per day."What this study shows is that, in a general population, there's no obvious harm, or benefit, to consuming coffee after a heart attack," said Ahmed El-Sohemy, an associate professor at the University of Toronto who has studied coffee intake and heart health. The problem is that certain individuals may benefit from some caffeine, while others may be harmed, according to El-Sohemy, who was not involved in the new study.Some research, for example, has linked coffee drinking to increased risks of high blood pressure in people who are naturally "slow metabolizes" of caffeine. But the reverse pattern has been seen in people who quickly process caffeine: more coffee, lower heart risks.
The findings, Lopez-Garcia said, "support the idea" that people with heart disease who already drink coffee do not have to give it up. But she also advised checking with your doctor, particularly if you have uncontrolled high blood pressure or other conditions that could be aggravated by caffeine -- like sleep problems or anxiety.
El-Sohemy was even more cautious. It is hard to make individual recommendations on safe coffee intake, according to the researcher, because of genetic variations in people's caffeine metabolism. "I don't see how any results can be interpreted from studies that don't take this genetic difference into account," El-Sohemy said. Tests for genetic variations in the enzyme that processes caffeine are not routinely available, he noted.
SOURCE: http://bit.ly/kUXi5R American Journal of Clinical Nutrition, online May 11, 2011.