Comparison of metabolism of vitamins D2and D3in children with nutritional rickets

Tom D. Thacher, Philip R. Fischer, Michael O. Obadofin, Michael A. Levine, Ravinder J. Singh, John M. Pettifor

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


Children with calcium-deficiency rickets may have increased vitamin D requirements and respond differently to vitamin D2 and vitamin D3. Our objective was to compare the metabolism of vitamins D2 and D 3 in rachitic and control children. We administered an oral single dose of vitamin D2 or D3 of 1.25mg to 49 Nigerian children - 28 with active rickets and 21 healthy controls. The primary outcome measure was the incremental change in vitamin D metabolites. Baseline serum 25-hydroxyvitamin D [25(OH)D] concentrations ranged from 7 to 24 and 15 to 34 ng/mL in rachitic and control children, respectively (p<.001), whereas baseline 1,25-dihydroxyvitamin D [1,25(OH)2D] values (mean ± SD) were 224 ± 72 and 121 ± 34 pg/mL, respectively (p<.001), and baseline 24,25-dihydroxyvitamin D [24,25(OH)2D] values were 1.13 ± 0.59 and 4.03 ± 1.33 ng/mL, respectively (p<.001). The peak increment in 25(OH)D was on day 3 and was similar with vitamins D2 and D3 in children with rickets (29 ± 17 and 25 ± 11 ng/mL, respectively) and in control children (33 ± 13 and 31 ± 16 ng/mL, respectively). 1,25(OH)2D rose significantly (p<.001) and similarly (p=.18) on day 3 by 166 ± 80 and 209 ± 83 pg/mL after vitamin D2 and D3 administration, respectively, in children with rickets. By contrast, control children had no significant increase in 1,25(OH)2D (19 ± 28 and 16 ± 38 pg/mL after vitamin D2 and D3 administration, respectively). We conclude that in the short term, vitamins D2 and D3 similarly increase serum 25(OH)D concentrations in rachitic and healthy children. A marked increase in 1,25(OH)2D in response to vitamin D distinguishes children with putative dietary calcium-deficiency rickets from healthy children, consistent with increased vitamin D requirements in children with calcium-deficiency rickets.

Original languageEnglish (US)
Pages (from-to)1988-1995
Number of pages8
JournalJournal of Bone and Mineral Research
Issue number9
StatePublished - Sep 2010


  • Calcium
  • Metabolic bone
  • Nutrition
  • Pediatric
  • Vitamin D

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Orthopedics and Sports Medicine


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