Can Multi-Vitamins Cause Asthma In Children?

You have to be careful where you get your news, these days.

Case in point: A US HSI member named Kelly wrote to me about a news bite that she's wary of, and rightfully so. Kelly writes:

'Last night as I was watching the news I was bothered by something that flashed across the screen in the ticker. The ticker read that there has been research done on the link between multi-vitamin supplements and asthma in infants. I know this is a US news item but could you please help us out and find the study that came to that conclusion and fill us in? I have given my child multi-vitamins since the day she got off formula and I intend to follow suit with my second child. Could you please help me find this study and let me know what it says?'

When a TV ticker (which is basically just a headline) in the US delivers the news, you can be sure that it will be long on shock value, and short on details. So Kelly did just the right thing. She questioned what she read, and then sought out more information, which may help keep her from making a rash decision.

Missing details

'Vitamins During Infancy May Raise Asthma Risk'

If you take that headline at face value, you'll be missing some important information in the fine print.

The study that Kelly read about appeared in the July 2004 issue of the journal Paediatrics. US researchers at the Children's National Medical Centre (CNMC) in Washington, examined data collected on more than 8,000 children over a period of three years as part of the National Maternal-Infant Health Survey. The CNMC team was specifically looking for a link between vitamin supplement use within the first six months and the development of asthma and allergies.

Analysis of the data showed that early vitamin supplementation is associated with asthma risk in black children. A similar link was found between vitamin use and food allergies in children who are fed exclusively with formula, but researchers couldn't determine whether the formula or the vitamins created more of the problem. A slight risk of food allergies was detected among kids who took vitamins at age three.

So what the TV ticker and the headlines didn't bother to mention was that, in fact, MOST children who receive vitamins at an early age will not be at risk of developing asthma. That's quite a different message than the one that Kelly was left with, or the one in the above headline.

Mountain from a molehill

Kelly's question made me wonder about vitamin supplements for children. So I asked HSI Panellist Dr Allan Spreen, to give us his reaction to the CNMC study. The first thing he noticed was that quite a few variables were involved in the study, but none were controlled for. So the results are somewhat scattershot.

For instance, the study states: 'Male gender, smoker in the household, child care, prematurity (<37 weeks), being black, no history of breastfeeding, lower income, and lower education were associated with higher risk for asthma. Child care, higher levels of education, income, and history of breastfeeding were associated with a higher risk for food allergies.'

Dr. Spreen notes that after studying 8,000 kids, only black children stood out, and even then, only in the first six months of life. And he adds: 'It's always entertaining to what lengths the medical profession will go to implicate supplements, especially when there are so many variables involved. The fact that they could only get one subset of the baby population involved makes them look even sillier, seems to me.'

Supplementing kids

As for general guidelines, Dr. Spreen offered these thoughts on giving vitamin supplements to children:

'I don't even use supplements in newborns, preferring instead to pump them into the breast-feeding mums, so I don't know what supplements they could have been using in the study. However, if they contained iron (and they most likely did) nothing else much matters. Asthma in kids has a fairly short list of causes, in my opinion: 1) Food allergy; 2) Inhalant allergy; 3) Nutrient deficiency. I'm sure there are other causes, but I'd rule those out first.

'In newborns the food should be breast milk... end of story. If there are asthma problems (and 0-6 months is pretty early to run into them), then the mother's diet must be examined, taking her off dairy, wheat, corn, possibly egg, possibly citrus, and anything else that she craves. And her supplements should not contain inorganic iron, which is the type that's in all the common, 100% RDA, junky products.

'For the older kids, the top nutrients on the list are: Vitamin C (possibly needing ascorbate form if ascorbic acid bothers the stomach), citrus bioflavonoids (which don't tend to be allergic even if the juice is), vitamin B-6, magnesium, and vitamin B-12.'

On the supermarket list: F. & V.

If Kelly happens to be a black woman, she should talk with her doctor about the CNMC study to weigh the benefits and risks before giving her children vitamin supplements at a young age. But she should also be aware of one more study, reported earlier this year in the American Journal of Respiratory Critical Care Medicine.

Researchers from Cornell University used data on more than 6,000 subjects (enrolled in the Third National Health and Nutrition Survey) to examine links between asthma and nutrients in children aged four to 16 years. The results: The intake of high levels of three dietary antioxidants (vitamin C, beta-carotene, and selenium) was associated with a reduced risk of asthma.

Just one more good reason for children to eat plenty of fresh fruits and vegetables.