Friday, February 22, 2008

Medical News: Vitamins Found No Help for Down's Syndrome Children

This is a new study that just came out. The full text can be seen at:

Of course, this doesn't change a thing with us! I know that giving my brother supplements has helped him tremendously!

I read the full text of the article and noted a couple interesting things.

The first quote here, they admit that they used low doses. They used some very low doses (5mgs of zinc, 10mcg of selenium, etc). I know, from experience especially, that higher doses of these nutrients are needed to see a benefit. I wonder if they checked the blood levels of zinc in these children? It didn't mention it in the full text. The only nutrient level tested, that was mentioned, was Vitamin E.

Also, in this first quote they admit that their low doses may not have been good enough to combat the biochemical issues in DS!

"One limitation of our study was the relatively low dose of supplements compared with commercially available preparations (Nutrivene-D and Euro TNI), which may have been inadequate to affect biochemical pathways."

I thought this was good too . . . In this second quote they admit that longer duration of supplementation may see effects.

"Our results do not exclude the possibility that subtle effects of supplementation on development might be detectable given longer term supplementation and follow-up."

Another thing I noticed is that they used RDA doses also, which is something that cannot necessarily be followed for those with DS. The reason being because the RDA is for "generally all healthy people," and therefore excludes those with something such as a genetic abnormality.

Vitamins Found No Help for Down's Syndrome Children

EXETER, England, Feb. 22 -- Children with Down's syndrome did not improve their development with the use of antioxidant vitamins, researchers here found.
Action Points

a.. Explain to interested patients that early vitamin supplementation for children with Down's syndrome may not improve development.

b.. Note that antioxidant supplements and folinic acid cannot be recommended for children with Down's syndrome based on the available evidence.
Psychomotor and language development scores were no better among British children with Down's given antioxidants or folinic acid (an active metabolite of folic acid) or both than among those who received neither, reported Stuart Logan, MBChB, of Peninsula Medical School, and colleagues online in BMJ.

Nor were biochemical measures of oxidative stress improved by the supplements in the randomized controlled trial.

Vitamin and mineral supplements marketed as holding substantial benefits for children with Down's are commonly used in the United States and Europe.

However, "parents who choose to give supplements to their children need to weigh their hope of unproved benefits against potential adverse effects from high dose, prolonged supplementation," the researchers wrote.

The lack of benefit from postnatal supplementation may not be surprising because Down's screening identifies differences between fetuses with and without trisomy 21 as early as 10 weeks' gestation, commented Tim Reynolds, M.D., of Queen's Hospital in Burton-on-Trent, England, in an accompanying editorial.

"Until evidence of any benefit of expensive vitamin supplements is available, they cannot be recommended," he said.

Developmental delay in Down's has been thought to result from oxidative neuronal damage, abnormal folate metabolism, or both, they said. The evidence, though, for nutritional interventions to counteract these effects has been poor, particularly in younger children, who had been thought to be most likely to benefit.

So the researchers undertook a well-designed study among 156 infants younger than seven months with Down's but no severe cardiac defects or other serious long-term illness.

They randomized the children to a daily oral dose of antioxidants (selenium 10 μg, zinc 5 mg, vitamin A 0.9 mg, vitamin E 100 mg, and vitamin C 50 mg) or folinic acid (0.1 mg) or both, or placebo.

All were given as a powder to be mixed with food or drink and were increased in dose by 30% after a child's first birthday.

After 18 months of follow-up, overall developmental scores as measured on the Griffiths mental developmental scales were similar between children given antioxidants and those who were not (mean 57.3 versus 56.1; adjusted mean difference 1.2 points, 95% confidence interval −2.2 to 4.6).

Likewise, developmental scores were similar for children randomized to folinic acid supplements or not (mean 57.6 versus 55.9; adjusted mean difference 1.7, 95% CI −1.7 to 5.1).

For language development after 18 months of follow-up, the number of words said or signed was similar for children given antioxidants versus none (ratio of means 0.85, 95% CI 0.6 to 1.2) and for those given folinic acid versus none (ratio of means 1.24, 95% CI 0.87 to 1.77).

Nor was there any difference in the age at which infants reached milestones in motor development.

Age at sitting without support was not significantly improved with antioxidants (hazard ratio 1.10, 95% confidence interval 0.77 to 1.56) or folinic acid (HR 1.25, 95% CI 0.88 to 1.78).

Standing did not start significantly earlier with antioxidants (HR 1.25, 95% CI 0.88 to 1.78) or folinic acid (HR 1.14, 95% CI 0.76 to 1.71).

To see whether the supplements could be having a subclinical effect, the researchers looked at biomarkers of oxidative stress in blood samples obtained blood at age one and urine samples.

Activity of antioxidant enzymes -- red cell superoxide dismutase and red cell glutathione peroxidase -- was not detectably different between treatment groups. Urinary isoprostane concentrations, a marker of lipid perioxidation, were also similar across groups, "indicating that supplementation did not affect oxidative stress."

The only short-term side effect in the study was an increase in vomiting among infants taking antioxidants (P=0.002), "but the side effects of higher dose preparations used over a long period are unknown."

Doses used in the study were at least 100% of the recommended daily allowance for all the vitamins and folinic acid, but still were relatively low compared with commercially available preparations, they noted.

"We were reluctant to use higher doses, as data on the safety of high doses for young children are lacking and high dose vitamin C may in fact exhibit pro-oxidant properties," Dr. Logan and colleagues wrote.

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