The effect of micronutrient supplements on female fertility:  a systematic review.
OBJECTIVE
Assessment of the influence of vitamins, trace elements and multivitamin supplements on female fertility.


METHODS
Systematic review of published controlled trials and cohort studies investigating the effect of vitamin supplements on female fertility. 13 studies with a total of 90,004 female test persons and patients.


METHODS
oral, preconceptional administration of single or combination of vitamin supplements;


METHODS
experimental studies, pharmacological studies, case control studies, case reports, reviews, meta-analysis. Women with chronic diseases, genetic or physical causes for (primary) sterility, couples with an impaired fertility of both partners; patients undergoing reproductive medicine care (insemination, in vitro fertilization, IVF, intracytoplasmatic sperm injection, ICSI). Determination of the proportion of women that experienced an influence of vitamin supplements on their fertility.


RESULTS
Thirteen relevant trials out of 37 studies were included. Some studies suggest a possible effect of micronutrients on female fertility. Emphasized results, for example, were an association between multivitamin substitution on pregnancy rate as well as higher vitamin B6 levels in fertile women compared to infertile women. One randomised controlled study showed a positive effect of vitamin C in women with luteal insufficiency.


CONCLUSIONS
Although some studies suggest possible effects of micronutrients on female fertility general recommendations are not possible since all studies had methodological or statistical limitations. Further investigations using evidence-based criteria are necessary to analyze and to confirm these non-evident appearances.
Department of Gynecological Endocrinology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
Donata
D
Grajecki
Birgit-Christine
BC
Zyriax
Kai J
KJ
Buhling
D019587:Dietary Supplements; D005260:Female; D005298:Fertility / Q000187:drug effects*; D006801:Humans; D018977:Micronutrients / Q000494:pharmacology*
D018977:Micronutrients