Efficacy of daily and monthly high-dose calciferol in vitamin D-deficient nulliparous and lactating women

Hussein F. Saadi, Adekunle Dawodu, Bachar O. Afandi, Reem Zayed, Sheela Benedict, Nicolaas Nagelkerke

Research output: Contribution to journalArticlepeer-review

93 Citations (Scopus)


Background: We previously found a high prevalence of vitamin D deficiency and low medication regimen compliance in Arab and East Indian women residing in the United Arab Emirates (UAE). The appropriate dosing regimen for improving vitamin D status in this population is not known. Objective: We aimed to determine the efficacy of daily and monthly supplementation with vitamin D 2, the only high-dose calciferol available in the UAE, in lactating and nulliparous women. Design: Healthy lactating (n = 90) and nulliparous (n = 88) women were randomly assigned to consume 2000 IU vitamin D2/d or 60 000 IU vitamin D2/mo for 3 mo. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured by radioimmunoassay at baseline and every month. Results: Most women had vitamin D deficiency [ie, 25(OH)D < 50 nmol/L] at study entry. Mean ± SD 25(OH)D concentrations at 3 mo were significantly higher than baseline in both lactating (39.8 ± 12.4 and 25.2 ± 10.7 nmol/L, respectively) and nulliparous (40.4 ± 23.4 and 19.3 ± 12.2 nmol/L, respectively) women (P < 0.001 for both). In total, vitamin D supplementation was effective in achieving serum 25(OH)D concentrations of ≥50 nmol/L in 21 (30%) of 71 women at endpoint. Conclusions: Oral vitamin D2 supplementation with 2000 IU/d or 60 000 IU/mo for 3 mo was safe, and it increased serum 25(OH)D concentrations significantly; however, only a small proportion of the women studied achieved concentrations of ≥50 nmol/L. This suggests that, when sunlight exposure is limited, doses of vitamin D 2 higher than those currently studied may be needed. Monthly dosing appears to be a safe and effective alternative to daily dosing.

Original languageEnglish
Pages (from-to)1565-1571
Number of pages7
JournalAmerican Journal of Clinical Nutrition
Issue number6
Publication statusPublished - Jun 1 2007
Externally publishedYes


  • 25(OH)D
  • 25-hydroxyvitamin D
  • Arab women
  • Lactating women
  • Nulliparous women
  • Vitamin D deficiency

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics


Dive into the research topics of 'Efficacy of daily and monthly high-dose calciferol in vitamin D-deficient nulliparous and lactating women'. Together they form a unique fingerprint.

Cite this