Related Experiment Video
Updated: Jul 16, 2025

Isolation of Mesenchymal Stem Cells from Human Alveolar Periosteum and Effects of Vitamin D on Osteogenic Activity of Periosteum-derived Cells
Published on: May 4, 2018
Oral Contraceptive Pills Increase Circulating 25-Hydroxy-Vitamin D Concentrations in Women Who Are Lactating
Lori L Huff1, Elizabeth V Schulz2, Colby D Richardson3
1Department of Pediatrics, Division of Neonatology, Medical University of South Carolina, Charleston, South Carolina.
Objective:
This article aims to determine the association between maternal 25-hydroxy-vitamin D [25(OH)D] status and intake of hormonal oral contraceptive pills (OCPs) in women who are lactating.
Study Design:
Women who were exclusively breastfeeding participated in a randomized controlled trial assessing vitamin D supplementation at 400, 2,400, or 6,400 international unit (IU)/d from 1 month through 7 months postpartum. This observational, secondary analysis assessed whether OCPs were associated with maternal 25(OH)D concentrations in women who are lactating. Multivariate regression models were used to predict 25(OH)D concentrations and create parameter estimates for each variable.
Results:
In a bivariate analysis, the use of OCPs at 4 months was associated with increased serum 25(OH)D (p = 0.02). OCPs' use at 7 months was associated with a higher trend in 25(OH)D, but this finding was not statistically significant (p = 0.1). In a multivariate regression model at 4 months, independent positive predictors of 25(OH)D concentrations were the use of OCPs (p = 0.03) and treatment with vitamin D at 6,400 IU/d (p ≤ 0.0001). Negative predictors were Black (p = 0.001) and Hispanic (p = 0.0001) race and ethnicity, and body mass index (BMI) greater than 30 (p = 0.0002). The same pattern occurred at 7 months, with more southern latitude as a positive independent predictor (p = 0.04) of 25(OH)D concentration.
Conclusion:
The use of OCPs was associated with greater 25(OH)D in women who are lactating. Additionally, treatment with vitamin D at 6,400 IU/d and southern latitude was associated with greater 25(OH)D in women who are lactating. Black and Hispanic race and ethnicity, and BMI greater than 30, were independently associated with lower 25(OH)D in women who are lactating.
Key Points:
· The association of OCP with serum 25(OH)D concentrations during postpartum lactation is unknown.. · OCPs' use was associated with higher 25(OH)D concentrations in postpartum women who are lactating.. · Treatment with vitamin D and southern latitude was associated with greater 25(OH)D in women who are lactating.. · Black and Hispanic, and BMI > 30 were associated with lower 25(OH)D in women who are lactating.. · Practitioners can counsel women who are lactating on OCPs' use and the positive effects on their 25(OH)D status..
Related Concept Videos
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin...
Birth Control Methods
Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...

