Mouse Study Indicates Vitamin D3 May Actually Inhibit Early Embryo Growth

LLU Center for Fertility’s research shows that because vitamin D3 acts differently on the two types of cells in an embryo, it may not be appropriate as part of infertility treatment.

Loma Linda, Calif. (January 30, 2018) – A recent study completed at Loma Linda University (LLU) found that while vitamin D3 had no effect on the placental cells in early-stage embryos, it inhibited growth of the embryo’s inner cell mass, which are destined to become the cells of the baby-to-be. The authors of the study, from LLU Center for Fertility & IVF and LLU Health OB/Gyn department, caution that the research was done in mouse embryos and that more research is needed before doctors can make firm recommendations on taking vitamin D3 supplements during early pregnancy.

Past studies have shown vitamin D3, the form of vitamin D naturally derived from diet and sun exposure, to be important to take during pregnancy for the health of both mother and baby. Those studies focused on maternal blood levels of the vitamin during different pregnancy stages. However, a more recent study published by the University of Messina in Italy, cautions against taking excessive vitamin D, as this may play a role in infertility.

“Our new study conducted at LLU differs from the previous studies because it looked at the effects of vitamin D3 on early embryos at the implanted state in a culture dish,” said Dr. Philip Chan, andrology lab director at LLU Center for Fertility & IVF.

“We hope that the findings stimulate more research into a ‘differential’ effect of vitamin D, meaning that taking vitamin D supplements is useful only in certain situations, under certain conditions and on the recommendations of doctors.”

The LLU team looked at mouse embryos at the early stage of development. At this stage, only the cells of the placenta (trophoblasts) and the cells of the baby-to-be (inner cell mass) can be distinguished under the microscope in a culture system. They found that vitamin D3 acted differently on these early embryos, not affecting the placental cells but causing the cells of the inner cell mass to become smaller than usual.

Along with Dr. Chan, Drs. Gihan Bareh, Kaimin Wei and Johannah Corselli with LLU Center for Fertility & IVF, and Dr. Emanuela Christati with the LLU OB/Gyn department, decided to start this study after seeing conflicting information on vitamin D3 in past studies. Some studies found low levels of vitamin D in blood in cases of miscarriages. Other studies have shown that vitamin D could cause cells to die, especially in breast cancer cells.

The research team wanted to test how vitamin D affects an embryo in an in vitro setting, meaning testing the biological process in a controlled laboratory environment rather than the natural setting. The type of vitamin D3 used in this study was at a concentration level found in over-the-counter vitamins.

This study, using mouse embryos in a lab setting, was just the beginning of looking further into the effects of vitamin D3 on the embryo. The LLU researchers say more work is necessary before establishing a definitive causal relationship between vitamin D3 supplementation and inhibition of embryo growth.

If their initial research is validated by further work, it will likely result in changes in the current routine recommendation by doctors regarding the use of vitamin D3 supplements during early pregnancy.

The findings of this study were shared at the American Society for Reproductive Medicine annual meeting with other fertility specialists.

About Loma Linda University Center for Fertility & IVF

Established in 1988, Loma Linda University Center for Fertility & IVF is one of the longest standing fertility centers in Southern California. Led by medical director John Jacobson, MD, the Center for Fertility provides personalized, quality fertility care to the Inland Empire. All fertility services are offered on-site including infertility testing, reproductive surgery, egg retrievals, embryo transfers and in vitro fertilization with the area’s leading lab.