Vitamin A levels and growth hormone axis

Vitamin A (VA) is required for normal growth and development retinoic acid may be the active metabolite through binding to nuclear receptors. Recently a correlation between nocturnal growth hormone (GH) secretion and VA was was found in short slowly growing children. We determined the 24-hour integrated concentration of GH (IC-GH), GH response to provocative stimuli, IGF-I, IGF-binding protein-3 (IGF-BP3) and GH-binding protein (GH-BP) in 34 prepubertal children (25 m/9 f) 5-10 years of age, height -2.5 to 1.5 SDS and body mass index -1.5 to 1.5 SDS for age and sex. Since folic acid, vitamin B12, IGF-I, cholesterol, triglycerides and VA carrier proteins were normal we assumed that no major nutritional deficiency existed. The correlation matrix of the variates tested were p < 0.05 for VA and IC-GH and p < 0.006 for IGF-BP3. It is suggested that VA might have a direct affect on both ICGH and IGF-BP3.