News

There appears to be a downside to the growing resurgence of mothers breastfeeding their infants - some babies are now suffering from vitamin D deficiency.

Researchers at Children's Hospital Boston conducted blood tests on 365 seemingly healthy babies and found 40 per cent of them had below optimal levels of the bone-building vitamin and 12 per cent were clearly deficient in the nutrient.

"Breast milk is the perfect food. It is the healthiest way to nourish an infant," said Catherine Gordon, lead researcher of the study published in the journal Archives of Pediatrics & Adolescent Medicine. "The problem is that many mothers are deficient in vitamin D and therefore their breast milk is deficient."

Vitamin D is produced naturally in skin exposed to sunlight. But many people living in northern latitudes have low levels of it in their bodies - especially during winter months, Dr. Gordon noted.

To make matters worse, pregnant women experience a drop in their vitamin D reserves as the bone structure of the developing fetus takes shape.

Only one child in the study had obvious signs of rickets - a once common childhood malady characterized by soft bones and physical deformities such as bowed legs.

But the absence of rickets does not mean parents or doctors shouldn't be concerned, Dr. Gordon said. In fact, X-ray images taken as part of the study revealed many infants showed evidence of reduced bone mineral content.

"The X-rays had a washed out-appearance ... because of the loss of minerals from their bones," she said.

She speculated that these children may be prone to fractures or osteoporosis later in life. A growing body of medical evidence suggests vitamin D also plays a key role in protecting the body from a wide range of diseases, including certain cancers, diabetes and multiple sclerosis.

Various pediatric associations and public health agencies say babies who are exclusively breastfed should be receiving vitamin D supplements. Health Canada, for instance, recommends 400 international units a day for these infants.

But that message don't seem to be reaching parents.

"We are trying to raise awareness," Dr. Gordon said. "It's so easy and inexpensive to supplement with vitamin D. And if it has a link to [the prevention of] many, many diseases, why not supplement children is my feeling. There is no harm."

DRUG WARNING

U.S. health regulators have launched a probe to determine whether certain drugs used to treat rheumatoid arthritis and Crohn's disease might boost the odds of developing cancer in children and young adults.

The medications belong to a class of drugs known as tumour necrosis factor blockers. The drugs - which include the top-selling brands Remicade (infliximab), Enbrel (etanercept), and Humira (adalimumab) - are designed to reduce inflammation by suppressing the body's disease-fighting immune system.

Regulators in both the United States and Canada have issued previous health warnings about these medications. But now the U.S. Food and Drug Administration is turning its attention to possible hazards for youth in particular.

On its website, the federal agency said it has received 30 reports of children and young adults developing cancer while taking the drugs over the past 10 years. About half of the cases involved lymphomas, including both Hodgkin's and non-Hodgkin's lymphoma.

"Health Canada is also reviewing this situation," spokesman Alastair Sinclair said in an e-mail.

The FDA expects to complete its probe within six months. "At the current time, the FDA believes that the potential benefits of the use of TNF blockers outweigh the potential risks," the agency said in a statement posted on its website. But, it added, "health-care providers, parents and caregivers should be aware of the possible risk of lymphoma and other cancers ... when deciding how best to treat these patients."

BUTTING OUT MAY GET EASIER

A genetic test may some day help determine the best method for smokers to kick the habit.

Scientists have long known that not everyone responds the same way to smoking cessation treatments. One technique might work well for one person, but fail for someone else.

So U.S. researchers scanned the genes of smokers who took part in a trial comparing nicotine replacement therapy with the smoking cessation drug Zyban. According to the findings published in Archives of General Psychiatry, smokers who successfully quit with nicotine replacement tended to have clusters of specific gene variants, while those who butted out with Zyban had other gene variants.

"Everyone has some version of these genes, but different people have distinct variants," explained researcher Jed Rose, of Duke University Medical Center in Durham, N.C.

"It helps us understand why some people are able to quit smoking [with a particular technique] more than others."

The researchers now hope to identify the genetic predictors for other treatments,including behavioural therapies.

"Within a few years, a simple blood test [providing a genetic profile] may provide physicians with enough information to recommend one treatment over another," Dr. Rose said in a statement released with the study.