Evidence check: Magnesium in the context of fertility

Magnesium is involved in fertility through roles in oocyte maturation, sperm motility, and hormone balance. Some studies link magnesium deficiency to reduced fertility, but evidence for routine supplementation to improve fertility is limited. In cases of confirmed deficiency, supplementation may be beneficial, but doses should not exceed 350–400 mg/day (adults) to avoid diarrhea and electrolyte imbalances. Most fertility studies are observational or small trials; large RCTs are lacking. Thus, evidence is moderate. A blood test (serum or RBC magnesium) is advisable before supplementing. Caveat: magnesium is not a standalone fertility treatment; lifestyle, diet, and other nutrients (e.g., zinc, folate) are equally critical.