Patients undergoing IVF treatment cycle at Queen Mary Hospital and Kwong Wah Hospital will be invited to participate in this study. Participating subjects will be randomized into either (i) vitamin D or (ii) placebo group in a 1:1 allocation ratio by computer-generated random numbers one month before IVF.~Subjects allocated to the vitamin D group will take vitamin D 50,000IU per week from recruitment for 4 weeks, followed by 50,000IU once every 2 weeks throughout the IVF cycle until fetal viability is confirmed at 6 weeks (if pregnant), after which they will be switched to Materna. If not pregnant, they will continue Vitamin D 50,000IU once every 2 weeks until 6 months from randomization, during which they can undergo frozen-thawed embryo transfer.~Subjects allocated to the placebo group will take placebo tablets which will be identical to the active drug. If pregnant and fetal viability is confirmed at 6 weeks, they will be switched to Materna. If not pregnant, they will continue the placebo tablets until 6 months from randomization, during which they can undergo frozen-thawed embryo transfer.~The clinician and patients will both be blinded to the randomization throughout the course of treatment. The live birth rate of the two groups will be compared.
This is a randomized-controlled trial evaluating the effect of the use of vitamin D supplementation on the live birth rate in women undergoing in vitro fertilization (IVF). The hypothesis is that administration of vitamin D can increase the live birth rate for women undergoing IVF.