Objective To determine if a single monthly supplement was as effective as a daily maternal supplement in increasing breast milk vitamin D to achieve vitamin D sufficiency in their infants. Patients and Methods Forty mothers with exclusively breastfed infants were randomized to receive oral cholecalciferol (vitamin D3) 5000 IU/d for 28 days or 150,000 IU once. Maternal serum, breast milk, and urine were collected on days 0, 1, 3, 7, 14 and 28; infant serum was obtained on days 0 and 28. Enrollment occurred between January 7 and July 29, 2011. Results In mothers given daily cholecalciferol, concentrations of serum and breast milk cholecalciferol attained steady levels of 18 and 8 ng/mL, respectively, from day 3 through 28. In mothers given the single dose, serum and breast milk cholecalciferol peaked at 160 and 40 ng/mL, respectively at day 1, before rapidly declining. Maternal milk and serum cholecalciferol concentrations were related (r=0.87). Infant mean serum 25(OH)D (±SD) increased from 17±13 to 39±6 ng/mL in the single dose group and from 16±12 to 39±12 ng/mL in the daily dose group (P=.88). All infants achieved serum 25(OH)D concentrations >20 ng/mL). Conclusion Either single dose or daily cholecalciferol supplementation of mothers provided breast milk concentrations that result in vitamin D sufficiency in breastfeeding infants.

This study compared serum cholecalciferol and 25-hydroxyvitamin D [25(OH)D] concentrations over four weeks in healthy, non-pregnant, non-lactating females aged 18-40 years, who were randomized to oral cholecalciferol 5,000 international units (IU) daily for 28 days or a single dose of 150,000 IU. The study was conducted in Rochester, MN in March and April of 2010. We found no difference in mean 25(OH)D between treatment groups on study day 0 or day 28 (p = 0.14 and 0.28, respectively). The daily group had 11 more days of detectable serum cholecalciferol than the single-dose group (p < 0.001). There was no difference observed in cholecalciferol area under the curve (AUC28) between groups (p = 0.49). However, The single dose group had a significantly greater mean 25(OH)D AUC28 compared with the daily group (p < 0.001).