A caution on excess vitamin D

People with long-term jaw pain disorders seem to be more sensitive than average to pain in other parts of their body, according to a study led by the University of Maryland School of Dentistry.

Researchers gave questionnaires and physical exams to 1,600 healthy people and 185 who had suffered from temporomandibular joint disorders (TMJ) for at least six months. The University of Maryland team developed special tools for testing pain and sensory perceptions.

TMJ disorders, which are not well understood, produce pain in the jaw and surrounding muscles.

The new study found that compared with the healthy control group, TMJ sufferers reported more headaches, low back pain, and chronic pain in areas other than the face in the previous year.

The findings do not suggest TMJ causes other types of pain, but sufferers may have "more complex patterns" of pain perception, stress control, and pain suppression, researchers say.

They say the study, in this month's Journal of Pain, could improve diagnosis and treatment of pain disorders in general. - Marie McCullough

University of Pennsylvania researchers were curious about why less than a third of lay witnesses to heart attacks attempt cardiopulmonary resuscitation (CPR).

They did in-depth interviews with 19 people. Two had no training in CPR; the others had taken courses within five years or longer ago.

The researchers, who presented their results earlier this month at the American Heart Association's annual scientific sessions, found that less than half of the interview subjects could accurately say when to perform CPR. Many described incomplete training or problems remembering what they had learned.

Nearly 80 percent lacked confidence in their CPR skills. Most had not heard of hands-only CPR and did not know it had been recommended for lay bystanders by the American Heart Association in 2010. (Rescue breaths are still recommended for children.) Once told about hands-only CPR, 89 percent said they would feel more confident about it than the standard method.

The researchers, led by Audrey Brewer of the Penn Emergency Medicine Department's Center for Resuscitation Science, said the study points to the need for better CPR training and wider promotion of hands-only CPR. - Stacey Burling

Vitamin D deficiency has been linked in recent years to dozens of conditions, from heart disease to psoriasis, and supplement sales have increased so fast you'd think they were magic pills.

But too much of anything can be problematic, according to researchers who have studied the benefits of the "sunshine vitamin."

For their new study, which was presented at an American Heart Association conference last week, researchers at the Intermountain Medical Center in Utah examined the records of more than 132,000 cardiology patients. They found that the risk of developing atrial fibrillation, a dangerous heart condition, was 21/2 times greater for those with "excess" levels of Vitamin D in their blood.

They defined "excess" as higher than 100 ng/ml, a blood level that most Americans could reach only by taking supplements containing more than 10,000 IU per day - 15 times the current federal dietary guideline.

There is no medical consensus on a "normal" blood level. These researchers defined it as 41 to 80 ng/ml. That range, well above what most doctors suggest, is in line with many holistic practitioners' recommendations. - Don Sapatkin

One in five Americans age 12 or older has a hearing loss severe enough to interfere with communication, according to an analysis by Johns Hopkins University researchers.

For their study, published in the Nov. 14 Archives of Internal Medicine, they used hearing test data gathered between 2001 and 2008 by the National Health and Nutritional Examination, a periodic federal survey.

Using the World Health Organization's definition of hearing loss - inability to hear speaking sounds of 25 decibels - the researchers estimated that about 30 million Americans, or 12.7 percent, had hearing loss in both ears. About 48 million, or 20 percent, have hearing loss in at least one ear, more than previous studies indicated.

"This gives us the real scope of the problem for the first time," said lead author Frank Lin. - M.M.