Autism Studies and Related Medical Conditions, January 2009 - TACA

is suggested that impaired systemic and mucosal immunity contributes to the increased
frequency and severity of intestinal infections seen in undernourished individuals."
88c. Lie C et al. Impact of large-dose vitamin A supplementation on childhood
diarrhoea, respiratory disease and growth. Eur J Clin Nutr. 1993 Feb;47(2):88-96.
PMID: 8436094
"One hundred and seventy-two 0.5-3.0-year-old children in a mountainous area of
northern Hebei Province of China were randomly assigned to a vitamin A
supplementation group (n = 98) or a control group (n = 74) for a 1 year double-blind
study. Capsules containing 200,000 IU vitamin A and 40 IU vitamin E were given to the
children in the experimental group 3 and 9 months after baseline examination. During
the 12 month study period, there was a significant reduction in the incidence of
diarrhoea (P < 0.01) and respiratory disease (P < 0.01) in the children of the
experimental group compared to the control. Risk of diarrhoea and respiratory disease
were respectively 2.5 and 3.4 times higher in the control children. Serum retinol and
IgA levels of the treatment group were significantly higher than that of control group (P
< 0.01) 7 weeks after first supplementation. There was no significant difference in
saliva IgA level between groups. No significant differences in growth were observed. It
was concluded that supplementation with large doses of vitamin A decreased the
incidence and severity of diarrhoea and respiratory disease in these children, possibly
through enhanced activity of the immune system, but had no effect on growth over 1
year."
88d. Sarkar J et al. Vitamin A is required for regulation of polymeric immunoglobulin
receptor (pIgR) expression by interleukin-4 and interferon-gamma in a human intestinal
epithelial cell line. J Nutr. 1998 Jul;128(7):1063-9. PMID: 9649586
"The secretory immunoglobulin A (IgA) antibody response to infections of mucosal
surfaces requires transport of IgA from the basal to apical surface of mucosal epithelial
cells by a specific transport protein, the polymeric immunoglobulin receptor (pIgR). We
have tested the hypothesis that the vitamin A metabolite all-trans retinoic acid (RA) is
required for the regulation of pIgR expression by the cytokines interleukin-4 (IL-4) and
interferon-gamma (IFN-gamma) in HT-29 cells… These data indicate that RA strongly
interacts with IL-4 and IFN-gamma to regulate pIgR expression in HT-29 cells,
suggesting that vitamin A may be required for proper in vivo regulation of IgA transport
in response to mucosal infections."
88e. Nikawa T et al. Vitamin A prevents the decline in immunoglobulin A and Th2
cytokine levels in small intestinal mucosa of protein-malnourished mice. J Nutr 1999
129(5):934-41. PMID: 10222382
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