Vitamin D status in pre-school children in rural Nepal

Abstract

Objective: Vitamin D plays a major role in Ca and bone metabolism, and its extraskeletal functions are being appraised. Although inadequate vitamin D concentrations have been reported in populations worldwide, too little is known about vitamin D status and its determinants among children in developing countries. We aimed to determine vitamin D status and its determinants in Nepalese children of pre-school age. Design: A community-based, cross-sectional study. Setting: Rural Nepal at latitude 27·39°N. Subjects: Healthy children (n 280) aged 12-60 months, selected randomly from the records of a vitamin A supplementation programme. Blood samples were collected using the dried blood spot technique and analysed for serum 25-hydroxyvitamin D (s-25(OH)D) concentration using liquid chromatographytandem mass spectrometry. Ca intake and background variables were assessed with a structured questionnaire. Results: Hypovitaminosis D, defined as s-25(OH)D concentration less than 50 nmol/l, was found in 91·1 % of the children. S-25(OH)D concentration was not related to gender, socio-economic indicators, sun exposure or nutritional status. Currently breast-fed children had higher s-25(OH)D concentrations (36·4 (SD 13·2) nmol/l) than those who were not (28·6 (SD 9·8) nmol/l, P < 0·001). Adjustment for sociodemographic factors did not alter the results. Conclusion: There is widespread vitamin D deficiency among pre-school children in a rural area of Nepal. In our sample, sociodemographic factors did not affect the vitamin D status of children, but prolonged breast-feeding was associated with higher s-25(OH)D concentrations. Further research is required to investigate the health consequences of poor vitamin D status for this population. Low levels of vitamin D are reported in diverse populations around the world (1-3) , with one review suggesting that as many as 14 % of the world's population have levels inadequate for general well-being (4) . Serum concentration of 25-hydroxyvitamin D (s-25(OH)D) is the standard assessment for vitamin D status in the body and s-25(OH)D concentration of 50 nmol/l or more is considered sufficient for optimal bone-related health outcomes by the Institute of Medicine (5) . Studies from Turkey, the Middle East and India have revealed that up to 50 % of children have vitamin D deficiency (6) . A number of determinants that affect s-25(OH)D concentration in children have been identified and include skin pigmentation, prolonged breast-feeding without vitamin D supplementation and low consumption of foods rich in vitamin D (7) . However, little is known about the vitamin D status of Nepalese children.Nepal is a predominantly Hindu nation bordering Tibet and India, located between the latitudes of 26°N and 31°N. Nepalese cultural values do not restrict sun exposure and about 300 d per year are sunny (8) . A few studies that have investigated vitamin D status in special groups in Nepal, such as pregnant women and alcohol-abusing populations, report a wide range of vitamin D deficiency prevalence rat...

Vitamin D status is associated with treatment failure and duration of illness in Nepalese children with severe pneumonia

“…The prevalence of insufficiency and deficiency was 2.5-fold higher in studies that included children with pneumonia compared with that in the population of healthy infants. The prevalence of poor vitamin D status was lower in the present study compared with that in other studies of healthy children in Nepal (12,32). There are currently no government programs or recommendations of vitamin D supplementation or food fortification for infants in Nepal (17,33).…”

“…Exclusive breast-feeding has been considered inadequate to prevent vitamin D deficiency (13,34), but recent reports show that vitamin D content in human milk is highly dependent on the mother's vitamin D status (35,36). Local sun-exposure habits associated with breast-feeding in Nepal, such as outdoor breast-feeding (12) and the tradition of sunbathing infants younger than 3 months (37), may therefore be plausible explanations for the relatively high plasma 25(OH)D concentration found in this study. We also found a stable plasma 25(OH)D concentration throughout the year, which may reflect adequate skin-synthesis of vitamin D across the seasons.…”

“…Vitamin D 3 is also derived from dietary sources such as oily fish, availability of which is often limited. Natural dietary sources of vitamin D 2 are also limited to some vegetables such as mushrooms, but both vitamin D 2 (12)(13)(14)(15). South Asia also has a high burden of respiratory tract infections among children (16,17).…”

Low Prevalence of Vitamin D Insufficiency among Nepalese Infants Despite High Prevalence of Vitamin D Insufficiency among Their Mothers

“…Cultural practices may impact vitamin D status in otherwise healthy populations, best illustrated in cultures where women cover their bodies and heads and/or spend a lot of time indoors [1,2,3,4,5]. There are also reports of poor vitamin D status among otherwise healthy populations in Nepal [6,7,8], despite over 300 sunny days a year [9], and no cultural avoidance of the sun. The increasing awareness of possible “extra-skeletal effects” of vitamin D on outcomes such as development of malignant, cardiovascular, autoimmune, metabolic and infectious diseases [10], and pregnancy outcomes and child growth [11], has resulted in an ongoing debate about optimal levels of vitamin D and an increased effort to identify predictors and implications of poor vitamin D status.…”

Prevalence of vitamin D deficiency/insufficiency among children and adolescents

“…5 Similarly an overall prevalence of 40%, with a higher (64.8% ) deficiency status among the adolescent girls, was reported in a study with 110 children in Ankara, Turkey 2 Prevalence is almost similar to a study by S Shrestha et al in Lalitpur Nepal, and they have reported prevalence of 78.2% among the young adults. 12 McGillivray et al reported 87% prevalence in East African immigrants living in Melbourne 21 and 90.8% prevalence reported by an Indian study among school aged girls is higher than the Shrestha's series 5,20 In our study, the comparisons between age groups in terms of Vitamin D levels revealed a very high 95.2% prevalence of vitamin deficiency/insufficiency among school aged children (6-10 yr) followed by 79.2% in adolescents (11-19yr). The cause behind such a high rate may be due to enrollment of entire symptomatic children, more indoor engagement, less sun exposure, air pollution and lack of vitamin supplementation.…”