Vitamin D recommendation for infants may be too high: Experts
Reported September 03, 2009
A new University of British Columbia study will look at whether giving pregnant women higher doses of vitamin D raises levels of the “sunshine” vitamin in breast milk so women won’t have to give supplements to their infants.
Eighty per cent of pregnant women in Canada take vitamin supplements but they are not getting enough vitamin D to pass on to their babies through breastfeeding, says Dr. Tim Green, a scientist in UBC’s food, nutrition and health department.
Green will take part in the study this fall which will measure vitamin D levels in 220 Vancouver women with different skin colours who are between 18 and 22 weeks pregnant and follow them until six months after lactation. Scientists will give them various doses of vitamin D and study how much of it makes it into the breast milk. They will also study the levels in the babies.
The reason for monitoring women with varying skin colour is because dark skin produces less vitamin D than light skin. The risk of vitamin D deficiency is especially high in dark-skinned people who live far from the equator, said Green.
Breast milk has been found to have very low levels of vitamin D, yet experts believe it is superior to baby formula, which is fortified with vitamins.
“We want to see if we can bump up the levels in the infant,” he said. “During the pregnancy and through lactation I think higher doses of vitamin D is probably sufficient to keep the infant levels of vitamin D high enough (without supplements.)”
Currently, Health Canada and the Canadian Paediatric Society recommend breastfed infants be given 400 International Units (IU) per day.
“It does seem high especially high considering that Health Canada recommends only 200 (IU) for a pregnant woman, who is considerably larger than an infant.”
This discrepancy in dosage is partly why giving infants supplements remains controversial.
Many parents choose not to follow the advice that exclusively breastfed babies should be given a vitamin D supplement every day.
Infact Canada, a national breastfeeding advocacy group, suggests that not all babies need the supplements because breast milk is natural and that too much vitamin D can be toxic. According to the group, the amount of sunshine needed is very low to maintain vitamin D levels. For example, an infant wearing only a diaper needs 30 minutes per week while in winter time a clothed infant not wearing a hat needs only two hours per week.
Rebekah Smith, Infact’s program coordinator, says Canadians should be wary of quick-fix solutions such as giving supplements to all babies, and that Health Canada’s recommendations imply that all exclusively breastfed infants are at risk.
Only a small minority of babies are at risk of vitamin D deficiency, she says, adding that breastfeeding in the park on a sunny day provides most infants with adequate vitamin D.
Health Canada and the Canadian Cancer Society both recommend not exposing an infant to sunlight, citing concerns over skin cancer.
Smith said it’s not appropriate for Health Canada to make blanket recommendations.
“That’s the problem – sometimes it’s just easier to make one statement for everyone because there’s a misconception that the public can’t understand something so complex and I think that’s a real shame because we have an obligation to weigh the risks and benefits when supplementing for vitamin D,” said Smith.
The group wants health officials to screen for at-risk infants and then talk specifically with the mother to see what kind of supplementation is appropriate, especially for those women who are mixing breastfeeding and formula.
“The fact that it’s a hormone is a reason to be a little more cautious when you are making recommendations for something like this. We just don’t have enough information on toxicity levels,” she said. “If women are using formula and supplementing with vitamin D that can be a real problem because they are getting such high levels.”
Registered massage therapist Anne May, 33, of Salt Spring Island, B.C., agrees with Infact and preferred a more natural approach when it came to giving supplements to her son Atticus, who was born last January.
May said she took vitamin D supplements when she was pregnant with Atticus and then, as an infant, she took him outside in the sun with some skin exposed for 20 minutes a day, even in the winter.
“The vitamin D you get at the drugstore has a lot of sugar in it and I didn’t like that,” she said. “I did it once in awhile, just in case, but I thought it would be better for him to process it naturally – it’s like vitamins, you don’t always absorb it.”
“We do have to take into consideration that we live farther north, but our family also has fairer skin,” she said, adding that her son was exclusively breastfed and never given formula.
Health Canada says it is “not practical, nor cost-effective” to screen all mothers and infants for vitamin D deficiency.
Vitamin D deficiency can lead to a rare bone deformity called rickets. However, most experts agree it can also lead to serious ailments later in life such as arthritis, cancer and multiple sclerosis.
The World Health Organization recommends exclusive breastfeeding for the first six months, then gradually introducing other nutritious foods.
Green suggests the government should look at increasing the range of foods that are fortified – for example, cheese, yogurt and bread – because there is a growing decline in milk consumption.
Source : Canwest News Service