Downs Syndrome

Blood levels of the antioxidant minerals selenium and zinc were normal in one study of people with Down syndrome,³ but others have found selenium^4,5 and zinc^6,7,8 levels to be low. In some studies more than 60% of patients with Down syndrome had low zinc levels.^9,10 A preliminary study of selenium supplementation in children with Down syndrome found that the antioxidant activity in the body improved; however, the implications of this finding on the long-term health of these people is unclear.¹¹ Zinc is critical for proper immune function, and in one preliminary study the majority of patients with Down syndrome examined had low zinc levels and low immune cell activity. Supplementation with zinc resulted in improved immune cell activity.⁹ In preliminary intervention trials, improved immune cell activity was associated with reduced rates of infection in Down syndrome patients given supplemental zinc in the amount of 1 mg per 2.2 pounds of body weight per day.^13,14 A controlled trial, however, did not find zinc, at 25 mg daily for children under 10 years of age and 50 mg for older children, to have these benefits.¹⁵ Zinc has other roles in the body; preliminary data have indicated that zinc supplementation, at 1 mg per 2.2 pounds of body weight per day, improved thyroid function in Down syndrome patients,^16,17,18 and increased growth rate in children with Down syndrome.¹⁹

Acetyl-L-carnitine is a compound that occurs naturally in the brain and plays a role in the normal functioning of the nervous system. In a preliminary trial, patients with Down syndrome were given 500 mg of L-acetyl-carnitine three times daily for 90 days and were observed to improve in visual memory and attention. Similar improvement was not seen in untreated patients, nor in patients with mental deficiency unrelated to Down syndrome who were also given L-acetyl-carnitine.¹⁹ More research into the effects of L-acetyl-carnitine in people with Down syndrome is needed.

Alzheimer’s disease, cataracts, autoimmune diseases, and a general increase in the pace of aging are all seen in people with Down syndrome.²² These associated conditions are similar in that they involve damage to body tissues by free radicals. It is believed that the genetic defect that produces Down syndrome increases the need for antioxidants (nutrients that prevent free-radical damage), and several studies of blood and urine biochemistry have shown this to be true.^22,24 In a preliminary study, vitamin E protected cells of people with Down syndrome from the oxidative damage to which they are most susceptible.²⁵ However, blood levels of vitamin C and vitamin E, two antioxidant nutrients, have not been found to be different when compared with those of healthy individuals.^24,27 The role of vitamin E and other antioxidants in treating Down syndrome needs further exploration.

The red blood cells of people with Down syndrome are unusual in ways that suggest either vitamin B12 or folic acid deficiency.^26,27,28 However, folic acid levels have been found to be normal in each of these studies, and only one study has found lower levels of vitamin B12 in Down syndrome as compared with healthy individuals.²⁹ Intervention trials using either vitamin B12 or folic acid have not been done.

In a double-blind trial, improvement was reported in the intellectual functioning of five children with Down’s syndrome given a daily high-potency multivitamin-mineral supplement.³⁰ This sparked interest in further research, but in a larger double-blind trial that followed, no benefit was observed.³¹ A later controlled trial found that multivitamin and mineral supplementation had no greater effect than did placebo in children with Down’s syndrome.³² A review of the research found no compelling reason to give multivitamin or B vitamin supplements to people with Down’s syndrome.³³

Blood levels of the antioxidant minerals selenium and zinc were normal in one study of people with Down’s syndrome,³⁴ but others have found selenium^35,36 and zinc^37,38,39 levels to be low. In some studies more than 60% of patients with Down’s syndrome had low zinc levels.^40,41 A preliminary study of selenium supplementation in children with Down’s syndrome found that the antioxidant activity in the body improved; however, the implications of this finding on the long-term health of these people is unclear.⁴² Zinc is critical for proper immune function, and in one preliminary study the majority of patients with Down’s syndrome examined had low zinc levels and low immune cell activity. Supplementation with zinc resulted in improved immune cell activity.⁴⁰ In preliminary intervention trials, improved immune cell activity was associated with reduced rates of infection in Down’s syndrome patients given supplemental zinc in the amount of 1 mg per 2.2 pounds of body weight per day.^44,45 A controlled trial, however, did not find zinc, at 25 mg daily for children under 10 years of age and 50 mg for older children, to have these benefits.⁴⁶ Zinc has other roles in the body; preliminary data have indicated that zinc supplementation, at 1 mg per 2.2 pounds of body weight per day, improved thyroid function in Down’s syndrome patients,^47,48,49 and increased growth rate in children with Down’s syndrome.⁵⁰

The red blood cells of people with Down syndrome are unusual in ways that suggest either vitamin B12 or folic acid deficiency.^50,51,52 However, folic acid levels have been found to be normal in each of these studies, and only one study has found lower levels of vitamin B12 in Down syndrome as compared with healthy individuals.⁵³ Intervention trials using either vitamin B12 or folic acid have not been done.