Vitamin D Supplementation at a Dose of 10 µg/Day in Institutionalized Children with Severe Motor and Intellectual Disabilities.

Vitamin D (VD) deficiency can lead to health-related consequences. This study determined the effects of VD administration in VD-deficient children with severe motor and intellectual disabilities (SMID). Twenty-eight subjects were included. Among them, 25 subjects with parental consent for VD administration were given 10 µg/day (400 IU/day) of VD in April 2021. Serum 25-hydroxyvitamin D [25(OH)D] levels were measured at least 30 days after the start of VD administration. The total VD intake, serum 25(OH)D levels, and ultraviolet (UV) exposure before the blood tests were investigated. The results showed that the median serum 25(OH)D levels were 8.7 ng/mL (4.3-17.2) and 24.0 ng/mL (7.8-39 ng/mL) from March to May in 2020 and 2021, respectively. Among the 25 subjects, 22 with UV exposure had >20 ng/mL serum 25(OH)D level, and 2 without UV exposure had <20 ng/mL serum 25(OH)D level. Three subjects who did not receive VD supplementation had <20 ng/mL serum 25(OH)D level. Taken together, VD supplementation (10 µg/day) is effective in children with SMID in institutional care. Moreover, it may be sufficient for children with UV exposure, but not for those without.