Gülay Karagüzel1, Beril Dilber, Gamze Çan, Ayşenur Ökten, Orhan Değer, Michael F Holick. 1. *Department of Pediatric Endocrinology †Department of Pediatrics, School of Medicine ‡Department of Public Health §Department of Biochemistry, Karadeniz Technical University, Trabzon, Turkey ||Vitamin D, Skin and Bone Research Laboratory, Section of Endocrinology, Nutrition and Diabetes, Department of Medicine, Boston University Medical Center, Boston, MA.
Abstract
OBJECTIVES: The aim of the study was to assess seasonal prevalence of vitamin D deficiency according to sex and to determine the relations between serum levels of 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) and sociodemographic characteristics in otherwise healthy schoolchildren during spring and autumn. METHODS: In a cross-sectional study, 746 healthy students aged between 11 and 18 years were recruited during spring (n = 375) and autumn (n = 371). Sociodemographic data were collected by a questionnaire. Serum 25(OH)D, PTH, calcium, phosphate, and alkaline phosphatase were measured. Serum 25(OH)D levels were categorized as <50 nmol/L (vitamin D deficiency) and <25 nmol/L (severe deficiency). RESULTS: Mean ± standard deviation 25(OH)D levels were 22.3 ± 10.5 nmol/L in girls and 28.5 ± 17.0 nmol/L in boys during spring (P < 0.001) and 36.5 ± 20.3 nmol/L in girls and 45.0 ± 18.5 nmol/L in boys during autumn (P < 0.001). The prevalence of vitamin D deficiency was 93% during spring and 71% during autumn. There was a negative correlation between 25(OH)D and PTH levels (P < 0.01). We determined a cutoff point of serum 25(OH)D in which the mean serum PTH concentration began to increase as 35.8 nmol/L (P < 0.0001). The age, sex, and calcium level were found to be independent predictors for vitamin D deficiency. CONCLUSIONS: Vitamin D deficiency is prevalent among healthy schoolchildren. It is noteworthy that 25(OH)D levels were significantly lower in girls and during autumn. We recommend vitamin D supplementation for children in addition to more time spent for outdoor activities for sensible sunlight exposure.
OBJECTIVES: The aim of the study was to assess seasonal prevalence of vitamin D deficiency according to sex and to determine the relations between serum levels of 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) and sociodemographic characteristics in otherwise healthy schoolchildren during spring and autumn. METHODS: In a cross-sectional study, 746 healthy students aged between 11 and 18 years were recruited during spring (n = 375) and autumn (n = 371). Sociodemographic data were collected by a questionnaire. Serum 25(OH)D, PTH, calcium, phosphate, and alkaline phosphatase were measured. Serum 25(OH)D levels were categorized as <50 nmol/L (vitamin D deficiency) and <25 nmol/L (severe deficiency). RESULTS: Mean ± standard deviation 25(OH)D levels were 22.3 ± 10.5 nmol/L in girls and 28.5 ± 17.0 nmol/L in boys during spring (P < 0.001) and 36.5 ± 20.3 nmol/L in girls and 45.0 ± 18.5 nmol/L in boys during autumn (P < 0.001). The prevalence of vitamin D deficiency was 93% during spring and 71% during autumn. There was a negative correlation between 25(OH)D and PTH levels (P < 0.01). We determined a cutoff point of serum 25(OH)D in which the mean serum PTH concentration began to increase as 35.8 nmol/L (P < 0.0001). The age, sex, and calcium level were found to be independent predictors for vitamin D deficiency. CONCLUSIONS:Vitamin D deficiency is prevalent among healthy schoolchildren. It is noteworthy that 25(OH)D levels were significantly lower in girls and during autumn. We recommend vitamin D supplementation for children in addition to more time spent for outdoor activities for sensible sunlight exposure.
Authors: Murat Cakir; Fatih Unal; Gonul Dinler; Masallah Baran; Hasan Ali Yuksekkaya; Gokhan Tumgor; Erhun Kasirga; Ayhan Gazi Kalayci; Sema Aydogdu Journal: World J Pediatr Date: 2015-10-11 Impact factor: 2.764
Authors: Shiao Wei Quah; Hazreen Abdul Majid; Nabilla Al-Sadat; Abqariyah Yahya; Tin Tin Su; Muhammad Yazid Jalaludin Journal: PLoS One Date: 2018-07-19 Impact factor: 3.240