Live birth 1.7 X more likely after IVF if good level of vitamin D – meta-analysis

Created August 2020

Women's vitamin D levels and IVF results: a systematic review of the literature and meta-analysis, considering three categories of vitamin status (replete, insufficient and deficient)

Hum Fertil (Camb). 2020 Aug 14;1-19. doi: 10.1080/14647273.2020.1807618

Florina Iliuta 1, Jose Ignacio Pijoan 2, Lucía Lainz 1, Antonia Exposito 1, Roberto Matorras 1 3 4

1. Vitamin D greatly improves Fertility {include}

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To investigate the influence of vitamin D status on in vitro fertilisation (IVF) results, a meta-analysis of 15 cohort studies of 3711 women undergoing IVF was performed. Women were classified into three groups according their vitamin D levels (≥30 ng/mL considered replete/sufficient; 21-29 ng/mL insufficient and <20 ng/mL deficient). Three different meta-analyses were performed: (i) sufficient vs deficient; (ii) sufficient vs 'insufficient + deficient'; (iii) 'sufficient + insufficient' vs deficient.

Comparing IVF outcomes in sufficient versus deficient groups (considering autologous and donor oocyte cycles together), we found women with sufficient vitamin D had significantly higher

  • biochemical pregnancy (OR = 1.43 [1.06-1.95]),

  • ongoing pregnancy (OR = 1.29 [1.02-1.64]), and

  • live birth (OR = 1.74 [1.31-2.31]) rates,

  • with a non-significant trend to a higher clinical pregnancy rate (OR = 1.31 [0.94-1.82]),

  • whereas implantation and miscarriage rates were similar.

When the meta-analysis was restricted to autologous oocytes , the parameters which had been significant in the joint analysis remained significant, and differences in

  • implantation (OR = 1.64, [1.17-2.29]) and

  • clinical pregnancy (OR = 1.47 [1.2-1.69]) rates became significant.

No significant differences were found when considering only cycles with donor oocytes. The sufficient + insufficient vs deficient and sufficient vs 'insufficient + deficient' comparisons identified significant differences in live birth rate.

The meta-analysis shows that sufficient vitamin D status is associated with better outcomes in IVF. Nonetheless, there are many demographic, geographic and clinical parameters that may be related to vitamin D status that need to be ascertained before concluding that the better results are due to the higher levels of vitamin D.

Tags: Fertility and sperm Meta-analysis