Reproductive Health & Fertility
Egg quality declines with age. Sperm quality declines with oxidative stress. Both respond to targeted nutritional intervention in human trials.
At a glance
The letters on this page
Eight interventions on this page. Three carry a letter; five are listed without one, with the reason.
How it is measured
What has been graded
Neural tube prevention: well-established RCT Randomized controlled trial: people are assigned to the treatment or a comparison by chance, so the groups differ only in what they received. It is the design that can show cause and effect. evidence. Methylated form preferred, bypasses MTHFR variants affecting ~40% of the population. Neural tube closure happens in early pregnancy, so the protective window begins before conception.
Not graded for this use. Not separately graded. EBL grades interventions at a studied dose and protocol, and this entry has no authored record behind it yet.
The Cochrane review of omega-3 supplementation in pregnancy (Middleton et al., 2018; PMID 30480773) reports a reduction in early preterm birth of roughly 42%. The DOMInO trial (Makrides et al., JAMA 2010, n=2,399; PMID 20959577) tested maternal depression and child neurodevelopment, not preterm birth. Algae-derived DHA preferred over fish oil in the preconception period. Evidence for direct oocyte quality improvement is limited. Grade reflects fetal outcome data.
Not graded for this use. Omega-3's graded uses are cardiovascular event endpoints in adults. Pregnancy outcomes are not graded.
Multiple RCTs link sufficient vitamin D status to improved IVF implantation rates and live birth outcomes. No optimal 25-OH D concentration is established; the National Academies sufficiency cutpoint is 20 ng/mL. Status is tested first. Deficiency is common and significantly affects outcomes.
Not graded for this use. None of vitamin D's graded uses covers fertility or pregnancy.
Xu et al. (2018 RCT, n=186; PMID 29587861): CoQ10 supplementation in poor ovarian responders improved oocyte and embryo quality in IVF cycles. Lafuente et al. (2013; PMID 23912751), a meta-analysis rather than a randomized trial: improved sperm motility and morphology in infertile men. Ubiquinol form preferred over 40. Oocyte maturation takes approximately 90 days, which is why timing is counted from before the IVF cycle.
Not graded for this use. CoQ10's B is scoped to chronic heart failure mortality and hospitalization. Fertility is not a graded use.
Multiple RCTs in PCOS populations show improved insulin sensitivity, restored ovulation, and improved oocyte quality. Most studied at a 40:1 myo-inositol to D-chiro-inositol ratio. Particularly relevant for anovulatory PCOS where insulin resistance is a driver.
Replenishment critical after OCP use. Supports progesterone synthesis and reduces risk of preeclampsia. Magnesium deficiency is common in reproductive-age women on hormonal contraceptives.
Rizk et al. (PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 15705376) RCT: NAC improved ovulation and pregnancy rates in clomiphene-resistant PCOS. For male factor: NAC reduces sperm DNA fragmentation and oxidative stress in multiple small RCTs. Lower evidence threshold. Benefit appears real but studies are small.
Small RCTs in poor IVF responders suggest melatonin reduces oxidative stress in follicular fluid and may improve oocyte quality. Evidence is limited to IVF populations. Not established for general fertility enhancement. Timing is a decision for your reproductive endocrinologist.
Not graded for this use. Melatonin's graded uses are delayed sleep phase disorder (B), jet lag (B), adult insomnia (C) and delirium prevention (C to D by setting). IVF outcomes in poor responders are not among them.
Cautions
- •Oral contraceptives have been associated with lower measured levels of vitamin B6, folate, vitamin B12, magnesium and zinc. The Drug-Nutrient Depletion tool lists the detail.
- •Metformin, often used in PCOS, is associated with lower vitamin B12 and may also be associated with lower folate.
- •Some studies have reported higher sperm DNA fragmentation during SSRI exposure; the clinical significance and reversibility remain uncertain. Before attempting conception, it is a question for the prescriber.
- •Anabolic steroids and exogenous testosterone suppress sperm production and can cause azoospermia. Tell your physician about any use.
Anything in this page is educational only. Fertility interventions interact with hormonal medications, IVF protocols, and underlying diagnoses in ways that require individualized medical supervision. Whether to start, stop or change a supplement for this condition, and how it fits with any medication you take, is a decision for your clinician (a reproductive endocrinologist where possible). The Drug-Nutrient Depletion tool is designed to help you prepare that conversation.
Disclosure
These statements have not been evaluated by the Food and Drug Administration. Any grade on this page describes the strength of published human trial evidence in the populations studied. It is not a recommendation for any individual and is not medical advice. Starting, stopping or changing any supplement or medication is a decision for your physician.