Determination Of Vitamin 25-Hydroxyvitamin D Deficiency And Insufficiency Cut-Off Values In Children

Objectives: There is no consensus on the lower and upper limits of 25-hydroxyvitamin D (25-OHD) deficiency and insufficiency. We determined the (25-OHD) deficiency and insufficiency cut-off values in children.Methods: The study examined 422 children aged 0-18 years old whose simultaneous parathormone (PTH) and (25-OHD) levels were measured at the paediatric outpatient clinics of our tertiary research hospital in Istanbul from January 1, 2014 to December 31, 2017. Those without chronic diseases were included in this cross-sectional retrospective study.Results: We found that the average serum (25-OHD) level was lower in girls. There were negative correlations between (25-OHD) and PTH and age. The level that decreased PTH below the upper level was 14.42 ng/mL and the 25(OH) D level that decreased it to the lowest limit was 26.61 ng/mL. The (25-OHD) level that caused maximum suppression of PTH was 22.5 ng/mL.Conclusions: The vitamin (25-OHD) deficiency (lowest value) and insufficiency (range) cut-off should be 14-23 ng/mL for children living in Istanbul. By age subgroup, the vitamin (25-OHD) deficiency and insufficiency cut-off values are 21-31, 15-21 and 13-18 ng/mL for those 0-2, 3-6 and 7-18 years, respectively.