You’re definitely not alone in questioning the hype! It’s true that outright magnesium deficiency in pregnancy is pretty rare if you’re eating a balanced diet, and most prenatal vitamins already cover your basic needs (usually around 30-50mg). Some studies link adequate magnesium levels to lower risk of leg cramps and possibly preterm labor, but evidence is mixed—routine supplementation for everyone isn’t universally recommended by big medical groups.
As for forms, glycinate and citrate are better absorbed and tend to be easier on the stomach than oxide, which can be more likely to cause diarrhea. Still, unless your provider says you’re low or you’re having specific symptoms, extra magnesium isn’t usually necessary. If anyone’s tried supplementing and noticed a difference (good or bad), I’d love to hear, too!