H Mazahery1, W Stonehouse2, P R von Hurst1. 1. Institute of Food, Nutrition and Human Health, Massey University, Auckland, New Zealand. 2. Commonwealth Scientific Industrial Research Organisation, Food and Nutrition Flagship, Adelaide, South Australia, Australia.
Abstract
BACKGROUND/ OBJECTIVES:Middle Eastern female immigrants are at an increased risk of vitamin D deficiency and their response to prescribed vitamin D dosages may not be adequate and affected by other factors. The objectives were to determine vitamin D deficiency and its determinants in Middle Eastern women living in Auckland, New Zealand (Part-I), and to determine serum 25-hydroxyvitamin D (serum-25(OH)D) response to two prescribed vitamin D dosages (Part-II) in this population. PARTICIPANTS/ METHODS:Women aged ⩾20 (n=43) participated in a cross-sectional pilot study during winter (Part-I). In Part-II, women aged 20-50 years (n=62) participated in a randomised, double-blind placebo-controlled trial consuming monthly either 50,000, 100,000 IUvitamin D3 or placebo for 6 months (winter to summer). RESULTS:All women in Part-I and 60% women in Part-II had serum-25(OH)D<50 nmol/l. Serum-25(OH)D was higher in prescribed vitamin D users than nonusers (P=0.001) and in Iranians than Arab women (P=0.001; Part-I). Mean (s.d.) serum-25(OH)D increased in all groups (time effect, P<0.001) and differed between groups (time × dosage interaction, P<0.001; 50,000 IU: from 44.0±16.0 to 70.0±15.0 nmol/l; 100,000 IU: 48.0±11.0 to 82.0±17.0 nmol/l; placebo: 45.0±18.0 to 54.0±18.0 nmol/l). Only 32% and 67% achieved serum-25(OH)D⩾75 nmol/l with 50,000 and 100,000 IU/month, respectively. Predictors of 6-month change in serum-25(OH)D were dose (B-coefficient±s.e.; 14.1±2.4, P<0.001), baseline serum-25(OH)D (-0.6±0.1, P<0.001) and body fat percentage (-0.7±0.3, P=0.01). CONCLUSIONS: Vitamin D deficiency/insufficiency is highly prevalent in this population. Monthly 100,000 IU vitamin D for 6 months is more effective than 50,000 IU in achieving serum-25(OH)D ⩾75 nmol/l; however, a third of women still did not achieve these levels.
RCT Entities:
BACKGROUND/ OBJECTIVES: Middle Eastern female immigrants are at an increased risk of vitamin Ddeficiency and their response to prescribed vitamin D dosages may not be adequate and affected by other factors. The objectives were to determine vitamin Ddeficiency and its determinants in Middle Eastern women living in Auckland, New Zealand (Part-I), and to determine serum 25-hydroxyvitamin D (serum-25(OH)D) response to two prescribed vitamin D dosages (Part-II) in this population. PARTICIPANTS/ METHODS:Women aged ⩾20 (n=43) participated in a cross-sectional pilot study during winter (Part-I). In Part-II, women aged 20-50 years (n=62) participated in a randomised, double-blind placebo-controlled trial consuming monthly either 50,000, 100,000 IU vitamin D3 or placebo for 6 months (winter to summer). RESULTS: All women in Part-I and 60% women in Part-II had serum-25(OH)D<50 nmol/l. Serum-25(OH)D was higher in prescribed vitamin D users than nonusers (P=0.001) and in Iranians than Arab women (P=0.001; Part-I). Mean (s.d.) serum-25(OH)D increased in all groups (time effect, P<0.001) and differed between groups (time × dosage interaction, P<0.001; 50,000 IU: from 44.0±16.0 to 70.0±15.0 nmol/l; 100,000 IU: 48.0±11.0 to 82.0±17.0 nmol/l; placebo: 45.0±18.0 to 54.0±18.0 nmol/l). Only 32% and 67% achieved serum-25(OH)D⩾75 nmol/l with 50,000 and 100,000 IU/month, respectively. Predictors of 6-month change in serum-25(OH)D were dose (B-coefficient±s.e.; 14.1±2.4, P<0.001), baseline serum-25(OH)D (-0.6±0.1, P<0.001) and body fat percentage (-0.7±0.3, P=0.01). CONCLUSIONS:Vitamin Ddeficiency/insufficiency is highly prevalent in this population. Monthly 100,000 IU vitamin D for 6 months is more effective than 50,000 IU in achieving serum-25(OH)D ⩾75 nmol/l; however, a third of women still did not achieve these levels.
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