Most women sleep well with 100–200 mg elemental magnesium at night, while daily totals should match age-based needs.

Adults generally need 400–420 mg (men) and 310–320 mg (women) of magnesium per day from all sources.

Women over 40 need about 320 mg of magnesium per day from food and drinks; supplements add only as needed.

For adult men, daily magnesium needs are 400–420 mg, based on age.

Most adults do well with 200–400 mg elemental magnesium daily for sleep support; start low at night and adjust with your clinician.

For vitamin D use, adults usually need 310–420 mg per day of magnesium from food and supplements.

During pregnancy, daily magnesium needs are 400 mg (ages 14–18), 350 mg (19–30), or 360 mg (31–50).

For adult women, daily magnesium from supplements should stay at or below 350 mg, with most needs met by food.

Most adults need 310–420 mg of magnesium each day, with higher needs during pregnancy and breastfeeding.

Typical study doses for hypertension range from 240–500 mg/day; keep supplements ≤350 mg/day unless your clinician advises.