Experts prescribe massive increase of vitamin D

By CanWest News ServiceSeptember 25, 2007 

A move to feed pregnant and nursing women 10 times more vitamin D than they get today may still not be enough to protect their babies from chronic diseases, especially in obese women, a top expert says.

The Canadian Paediatric Society is recommending pregnant and lactating women consider taking 2,000 IU (international units) of vitamin D daily, especially during winter, to protect their babies from a litany of illnesses later in life.

The current Health Canada recommendation is 200 IU a day for adults under 50 - including pregnant and nursing mothers.

Dr. Bruce Hollis, professor of pediatrics and director of pediatric and nutritional sciences at the Medical University of South Carolina who has studied vitamin D in humans for 30 years, called the society's new position statement "a remarkable change."

But he said many women of childbearing age, especially in Canada, are "absolutely deficient" in vitamin D.

"To say (2,000 IU) daily will replete everybody probably isn't totally accurate, and I say with confidence it's not enough to ensure breast-feeding infants get enough (vitamin D) through human milk."

Vitamin D deficiencies in early life have been linked with an increased risk of small babies, asthma, diabetes, autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and inflammatory bowel disease, dental malformations and the development of certain cancers.

In two U.S. government-funded studies, Hollis is studying vitamin D supplementation of up to 6,000 IU daily in nursing women, and 4,000 units per day in pregnant women. So far "not one single adverse event" has been observed in women on the highest doses, he said in an interview.

The pediatric society says even experimental doses of up to 10,000 IU per day for five months in pregnancy didn't lead to levels in the toxic range.

After years of telling people to screen out the sun, doctors are finding a host of reasons to load up on the "sunshine vitamin."

First came cancer: In June, the Canadian Cancer Society for the first time recommended adult Canadians lower their cancer risk by taking 1,000 IU daily. The vitamin has been linked with a lower risk of cancers of the breast, lung and colon.

Now, pregnancy: Vitamin D deficiency in mothers and babies continues to be a problem in Canada, particularly among aboriginal women, the pediatric society says, and infants under one are especially vulnerable if they are breast fed.

Hollis said vitamin D is important for brain development and to build tolerance against autoimmune diseases. It also protects the mother from uterine infections that can lead to pre-eclampsia - a common disorder that causes high blood pressure and can lead to poor fetal growth and fatal complications in moms and babies if not treated.

Oily fish such as salmon and sardines contain vitamin D and the vitamin is in fortified milk and margarine. But food alone can't provide sufficient vitamin D, especially in babies.

A daily vitamin D supplement of 400 IU per day has been recommended for breastfed infants in Canada for decades, largely to prevent rickets, 104 confirmed cases of which were reported in Canada between 2002 and 2004.