Vitamin A supplementation in preschool children and risk of hearing loss as adolescents and young adults in rural Nepal: randomised trial cohort follow-up study

Abstract

Objective To determine whether vitamin A supplementation administered in the preschool years can lower the risk of hearing loss in adolescence and adulthood.Design Follow-up study of adolescents and young adults who, as preschool aged children in 1989, were enrolled into a cluster randomised, double blinded, placebo controlled trial of vitamin A supplementation. Setting South central, rural Nepal.Participants 2378 adolescents and young adults aged 14 to 23, representing 51% of those who finished the original trial and 71% of those living in the study area in 2006.Interventions Every four months for 16 months preschool children were visited at home, given an oral 200 000 IU dose of vitamin A (half dose at age 1-11 months, quarter dose at <1 month) or placebo and the parents were queried about any childhood illnesses in the previous week, including purulent discharge from the ears.Main outcome measures Prevalence of mild or worse hearing loss (≥30 dB) in the most affected ear and tympanometric measures of middle ear function (peak height, ear canal volume, and gradient).Results During the original trial, the prevalence of middle ear infection during the preschool years did not differ between the supplement groups. By adolescence and early adulthood, a non-significant 17% reduction in hearing loss occurred among those who had periodically received vitamin A compared with placebo as preschool aged children (odds ratio 0.83, 95% confidence interval 0.62 to 1.12). Among participants with any ear discharge in early childhood, vitamin A supplementation was associated with a reduced risk of hearing loss, by 42% (0.58, 0.37 to 0.92) compared with controls, after adjusting the confidence interval for the design effect of the original trial. Abnormal tympanometric peak height of the middle ear system was less likely among participants supplemented with vitamin A in childhood. ConclusionIn undernourished settings, periodic, high dose vitamin A supplementation may reduce the risk of hearing loss associated with purulent ear infections in early childhood.

Prevalence of Vitamin A Deficiency in South Asia: Causes, Outcomes, and Possible Remedies

“…The colostrum discarded usually results in failure to maintain normal vitamin A levels among infants. One recent study confirmed the role of high dose of vitamin A supplementation to significantly reduce progressive hearing loss associated with purulent ear infections in early childhood (18). …”

Hearing Loss Is Associated With Decreased Nonverbal Intelligence in Rural Nepal

“…This subcohort had participated as preschoolers in a placebo-controlled vitamin A supplementation trial in 1989–91 (22) and were followed in an ear health and hearing survey from 2006–2008 (23). …”

“…Wald p -values were reported for categorical variables. Due to our previously reported effect of vitamin A allocation reducing hearing loss attributed to otitis media (23), interaction by childhood trial allocation to vitamin A vs placebo was assessed in the linear regression model and was not found to be present.…”

Vitamin A and Related Compounds in the Prenatal and Postnatal States: A MaternalNeonate Focused Review

“…In chronically undernourished populations, vitamin A supplementation during pregnancy has been associated with decrease hearing loss due to ear infections in the offspring [31] and improved growth outcomes [32]. Supplementation of vitamin A during pregnancy in an undernourished population in Nepal has also been associated with improved offspring lung function [33], however; it did not decrease risk of asthma [34].…”