Serum Levels of Vitamin D Metabolites in Children Receiving Total Parenteral Nutrition

Serum levels of 25‐hydroxyvitamin D (25‐OHD) and 1,25‐dihydroxyvitamin D (1,25‐(OH)2D) were measured on 19 occasions in seven children receiving total parenteral nutrition (TPN). The daily intakes of vitamin D 3 ranged from 44 to 540 IU/day, and all serum samples were obtained after the same daily intake of vitamin D 3 for more than 1 month. There was a significant positive correlation between serum 25‐OHD levels and parenteral vitamin D3 intakes ( r = 0.90, p < 0.01). In this study, serum 25‐OHD levels in all cases taking 200 to 360 IU/day of vitamin D 3 were within the normal range. On the other hand, no significant correlation was found between serum 1,25‐(OH) 2 D levels and vitamin D 3 intakes, and serum 1,25‐(OH) 2 D levels were normal or elevated in all cases. (Journal of Parenteral and Enteral Nutrition 10:191–194, 1986)