8 observed an 18.4% prevalence of VAD in preschoolers with DS aged 2 to 6 years, as opposed to a prevalence of 4% among children without the syndrome. Children with Down Syndrome (DS) are also at a higher risk to develop VAD. The nutritional status related to vitamin A needs to be screened and monitored, especially in populations at higher risk of VAD, such as preschoolers and pregnant and nursing women, because of the greater nutrient demand, 7 so that preventive and early diagnosis strategies may be effective. These components of the GH-IGF system axis, together with genetic inheritance, directly determine growth and development. In addition, some studies have observed a positive correlation between the serum concentrations of retinol and insulin-like growth factor 1 (IGF-1), including in newborns and infants, 5, 6 whose production is influenced by GH and by nutritional status. 4 In humans, serum retinol concentrations are positively correlated with nocturnal GH secretion. Retinoic acid can stimulate the secretion of growth hormone (GH) in vitro in rat pituitary cells. Thus, VAD has negative effects on the immunological response and is associated with greater morbidity-mortality due to infections, in addition to interfering with the processes of child growth and development. 1 Subclinical VAD starts before the onset of ocular clinical signs and leads to a reduction of immune response and cell differentiation and multiplication. Vitamin A deficiency (VAD) represents a global public health problem, affecting 190 million preschoolers each year in the world, and 4.4 million children have a diagnosis of xerophthalmia, mainly in developing countries.
ConclusionĪ high prevalence of VAD and deficient retinol was observed and there was a positive correlation between serum retinol and IGF-1. A moderate positive correlation was observed between pre-intervention retinol and IGF-1 (ρ = 0.37 p-value = 0.01). No association was observed between VAD and IGF-1 deficiency. Mean IGF-1 were 103.5 ng/mL (SD = 913) for the group with VAD and 116.3 ng/mL (SD = 54.9) for the group with no VAD (p-value = 0.85) 8.5% (4/47) of the children showed deficient IGF-1, but without VAD. VAD prevalence was 25.5% (12/47), and 74.5% (35/47) of the children had deficient retinol before the intervention. Weight, height, and information about fever and/or diarrhea were obtained at the beginning of the study. C-reactive protein (CRP) was determined at the beginning of the study. Retinol serum concentration ≤ 0.70 µmol/L and IGF-1 serum concentration below the 3rd percentile for sex and age were considered to represent deficiency. VAD was determined by the relative dose-response (RDR) test. MethodsĬross-sectional study was conducted on 47 children with DS aged 24 to 72 months, in Ribeirão Preto, Brazil. To determine the prevalence of vitamin A deficiency (VAD) and serum concentrations of retinol, correlating them with IGF-1 concentrations in preschoolers with DS.