RESUMO
Abstract Background: Vitamin D (VD) deficiency has been inversely associated with parathyroid hormone (PTH) levels in the adult population but not in children and adolescents. This study aimed to report VD concentration and its correlation with PTH levels in a sample of healthy Mexican children. Methods: We conducted a cross-sectional study with 275 healthy Mexican subjects aged 2 to 17 years to estimate the status of 25-(OH)-D and its correlation with PTH levels. The 25-(OH)-D levels were estimated by liquid chromatography-tandem mass spectrometry and PTH by radioimmunoassay. Results: Subjects were categorized as young children (2 to 5 years), school children (6 to 10 years), and adolescents (11 to 17 years). The median concentration of 25-(OH)-D in young children was 27.4 ng/ml; in school children, 25.6 ng/ml; and adolescents, 24.7 ng/ml. VD levels < 20 ng/ml were found in only 10.5% of the participants. Only 3% of the young children showed VD deficiency, in contrast to 10% of school children and 21% of adolescents (p ≤ 0.05). PTH was found within normal ranges in 95.6% of the studied population. VD levels < 20 mg/dl were found in 25.8% of children with overweight or obesity (p = 0.009). Conclusions: VD levels < 20 ng/ml were observed in 10% of the studied group, but this percentage increased with age: 21% of the adolescents showed VD levels < 20 ng/ml. No correlation with PTH levels was found. The VD values reported in this study are lower than those previously reported in Mexican children.
Resumen Introducción: La deficiencia de vitamina D se ha asociado inversamente con la concentración de hormona paratiroidea (PTH) en los adultos, pero no en los niños y adolescentes. El objetivo de este estudio fue reportar la concentración de vitamina D y su correlación con la concentración de PTH en una muestra de niños mexicanos sanos. Métodos: Se llevó a cabo un estudio transversal con 275 mexicanos sanos de 2 a 17 años de edad en quienes se estimaron las concentraciones de 25-(OH)-D utilizando cromatografía líquida con espectrometría de masas y de PTH por radioinmunoensayo, y su correlación. Resultados: Los participantes se categorizaron como prescolares (2 a 5 años), escolares (6 a 10 años) y adolescentes (11 a 17 años). La mediana de la concentración de 25-(OH)-D en los prescolares fue de 27.4 ng/ml, en los escolares de 25.6 ng/ml y en los adolescentes de 24.7 ng/ml. Solo en el 10.5% de los participantes se encontraron valores de vitamina D < 20 ng/ml. En contraste con el 10% de los escolares y el 21% de los adolescentes, solo el 3% de los prescolares mostraron deficiencia de vitamina D (p ≤ 0.05). La PTH se encontró dentro de los límites normales en el 95.6% de la población estudiada. Se encontraron concentraciones de vitamina D < 20 mg/dl en el 25.8% de los niños con sobrepeso y obesidad (p = 0.009). Conclusiones: Solo en el 10% de los participantes se encontraron concentraciones de vitamina D < 20 ng/ml, pero este porcentaje aumento con la edad y se hallaron valores < 20 ng/ml en el 21% de los adolescentes. La PTH se encontró dentro de los valores normales. Las concentraciones de vitamina D en este estudio resultaron menores que las previamente reportadas en niños mexicanos.
RESUMO
BACKGROUND: Vitamin D (VD) deficiency has been inversely associated with parathyroid hormone (PTH) levels in the adult population but not in children and adolescents. This study aimed to report VD concentration and its correlation with PTH levels in a sample of healthy Mexican children. METHODS: We conducted a cross-sectional study with 275 healthy Mexican subjects aged 2 to 17 years to estimate the status of 25-(OH)-D and its correlation with PTH levels. The 25-(OH)-D levels were estimated by liquid chromatography-tandem mass spectrometry and PTH by radioimmunoassay. RESULTS: Subjects were categorized as young children (2 to 5 years), school children (6 to 10 years), and adolescents (11 to 17 years). The median concentration of 25-(OH)-D in young children was 27.4 ng/ml; in school children, 25.6 ng/ml; and adolescents, 24.7 ng/ml. VD levels < 20 ng/ml were found in only 10.5% of the participants. Only 3% of the young children showed VD deficiency, in contrast to 10% of school children and 21% of adolescents (p ≤ 0.05). PTH was found within normal ranges in 95.6% ofthe studied population. VD levels < 20 mg/dl were found in 25.8% of children with overweight or obesity (p = 0.009). CONCLUSIONS: VD levels < 20 ng/ml were observed in 10% of the studied group, but this percentage increased with age:21% of the adolescents showed VD levels < 20 ng/ml. No correlation with PTH levels was found. The VD values reported inthis study are lower than those previously reported in Mexican children.
