A new study has overturned the belief that women who take extra vitamin C and E when pregnant protect their babies from wheezing and asthma.
The findings by Asthma UK-funded study, carried out by Professor Anne Greenough and colleagues at King’s College London and Imperial College London, England, is in stark contrast with observational studies that concluded children born to women with low levels of vitamin E in their blood were more likely to experience wheezing and asthma.
A total of 643 women took part in the study, receiving either vitamin supplements or identical-looking placebo tablets during pregnancy. Analysis of a questionnaire completed when their children were two showed that taking vitamin C and E supplements had no impact on their children’s risk of wheezing or eczema.
The women who took part in the study had been involved in a previous study and were all recognised as being at high risk of pre-eclampsia. The levels of vitamins C and E the women received were far higher than those found in most vitamin pills, the report, published in this week’s edition of Thorax said.
Dr Elaine Vickers, research relations manager at Asthma UK said: “Pregnant women are bombarded with advice on how to safeguard their child’s health, and there is a lot of misleading hype around the possible benefits of antioxidant vitamins. Studies like this are therefore essential to help women make well-informed decisions.
“This study shows that taking high doses of vitamins C and E will not help pregnant women protect their children against asthma or other lung conditions.”
She urged anyone with any concerns or queries to look at the NHS Choices website or visit their doctor. Alternatively, the Asthma UK Adviceline on 0800 121 62 44 or website can offer advice.
* A second study today warns that a mother’s anger or irritation can aggravate a child’s symptoms.
Japanese researchers studied more than 200 mothers for a year for the research, published in BioPsychoSocial Medicine.
Researcher Jun Nagano, from the Kyushu University Institute of Health Science, Fukuoka, Japan, said: "Our results suggest that the mothers of younger children may be advised not to worry about falling into unfavourable parenting styles, but to pay more attention to the reduction of their own stress; and that the mothers of older children may be encouraged to increase their own wellbeing via proper egocentric and self-defensive activities, being careful to avoid too much interference with their children."
The parenting attitudes and the stress of mothers predict the asthmatic severity of their children: a prospective study. Jun Nagano, Chikage Kakuta, Chikako Motomura, Hiroshi Odajima, Nobuyuki Sudo, Sankei Nishima and Chiharu Kubo. BioPsychoSocial Medicine October 7 2010
* Healthy children with normal vitamin D levels do not gain any health benefits if they take supplements of the vitamin, researchers say.
However, children with low levels of the vitamin D, which helps the body absorb calcium from food, reduces losses of calcium from the body and encourages calcium deposition into bone, may benefit from taking additional tablets.
Dr Tania Winzenberg, from the Menzies Research Institute Tasmania, Hobart, Australia, and her colleagues examined existing randomised controlled trials research studies that had compared giving children vitamin D supplements with giving a placebo.
They looked at six studies that involved a total of 343 participants who were given a placebo and 541 who took vitamin D for at least three months and were aged between one month and 19 years old.
“Vitamin D supplementation had no statistically significant effects on bone density at any site in healthy children,” says Dr Winzenberg, who was study leader of the new Cochrane Systematic Review.
“There was, however, some indication that children who had low levels of vitamin D in their blood might benefit from supplementation.
“We now need randomised controlled studies focused on vitamin D deficient children to confirm if vitamin D supplements would help this particular group.”
This study adds to the existing reports published in The Cochrane Library that look at the effect of giving vitamin supplements to children. These include investigations on whether vitamin C can prevent colds or help children with asthma, and whether vitamins A and D can help children with cystic fibrosis.
Winzenberg TM, Powell S, Shaw KA, Jones G. Vitamin D supplementation for improving bone mineral density in children. Cochrane Database of Systematic Reviews 2010, Issue 10. Art. No.: CD006944. DOI: 10.1002/14651858.CD006944.pub2.
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