The effect of high-dose vitamin D supplementation on serum vitamin D levels and milk calcium concentration in lactating women and their infants.
OBJECTIVE
Improve vitamin D status in lactating women and their recipient infants, and measure breast milk calcium concentration [Ca] as a function of vitamin D regimen.


METHODS
Fully breastfeeding mothers were randomized at 1 month postpartum to 2000 (n = 12) or 4000 (n = 13) IU/day vitamin D for 3 months to achieve optimal vitamin D status [serum 25(OH)D > or =32 ng/mL (80 nmol/L)]. Breast milk [Ca], maternal and infant serum 25(OH)D and serum Ca, and maternal urinary Ca/Cr ratio were measured monthly.


RESULTS
Mothers were similar between groups for age, race, gestation, and birth weight. 25(OH)D increased from 1 to 4 months in both groups (mean +/- SD): +11.5 +/- 2.3 ng/mL for group 2000 (p = 0.002) and +14.4 +/- 3.0 ng/mL for group 4000 (p = 0.0008). The 4000 IU/day regimen was more effective in raising both maternal and infant serum levels and breast milk antirachitic activity than the 2000 IU/day regimen. Breast milk [Ca] fell with continued lactation through 4 months in the 2000 and 4000 IU groups. Decline in breast milk [Ca] was not associated with vitamin D dose (p = 0.73) or maternal 25(OH)D (p = 0.94). No mother or infant experienced vitamin D-related adverse events, and all laboratory parameters remained in the normal range.


CONCLUSIONS
High-dose vitamin D was effective in increasing 25(OH)D levels in fully breastfeeding mothers to optimal levels without evidence of toxicity. Breast milk [Ca] and its decline in both groups during 1 to 4 months were independent of maternal vitamin D status and regimen. Both the mother and her infant attained improved vitamin D status and maintained normal [Ca].
Basile
Laura A
LA
Department of Pediatrics/Division of Neonatology, Medical University of South Carolina, Charleston, SC 29425, USA. basile@musc.edu <basile@musc.edu>
Taylor
Sarah N
SN
Wagner
Carol L
CL
Horst
Ron L
RL
Hollis
Bruce W
BW
D000328:Adult; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism; D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D003404:Creatinine / Q000652:urine; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena / Q000502:physiology*; D007231:Infant, Newborn; D007774:Lactation / Q000378:metabolism; D039382:Maternal Nutritional Physiological Phenomena / Q000502:physiology*; D008895:Milk, Human / Q000737:chemistry*; D009751:Nutritional Requirements; D009752:Nutritional Status; D011446:Prospective Studies; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood* / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000517:prevention & control
D050071:Bone Density Conservation Agents; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D003404:Creatinine; D002118:Calcium