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Magnesium for Women Over 40

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The short answer

Magnesium for Women Over 40? Most women over 40 are subclinically magnesium-deficient. 300-400 mg/day of magnesium glycinate or citrate supports sleep, mood, muscle recovery, and bone mineralization. It is one of the few supplements with broad evidence for perimenopausal symptom relief.

The short answer

Most women over 40 are subclinically magnesium-deficient. 300-400 mg/day of magnesium glycinate or citrate supports sleep, mood, muscle recovery, and bone mineralization. It is one of the few supplements with broad evidence for perimenopausal symptom relief.

The science

Magnesium is a cofactor in 300+ enzymatic reactions, including those involved in muscle relaxation, neurotransmitter regulation, and bone mineralization. Women over 40 consistently consume 20-30% below RDA, and the absorption rate drops further with age. Magnesium deficiency manifests as muscle cramping, restless sleep, anxiety, constipation, and worsened blood pressure — many of the same complaints attributed to perimenopause generally.

Practical guidance

  • Take 300-400 mg/day of glycinate or citrate (better tolerated, well-absorbed)
  • Avoid magnesium oxide — high dose appears on the label but absorption is poor (<5%)
  • Take in the evening — magnesium has a mild sedative effect
  • Food sources: pumpkin seeds (190 mg/oz), spinach (160 mg/cup cooked), almonds (80 mg/oz), dark chocolate (65 mg/oz)
  • Citrate also relieves constipation; glycinate is gentler if bowels are fine
  • Combine with food — empty-stomach magnesium can cause GI upset

Common mistakes

  • Buying magnesium oxide because it has the highest mg per pill — most of it is unabsorbed
  • Mega-dosing — above ~600 mg/day diarrhea is common; that is your absorption ceiling
  • Stopping when symptoms improve — magnesium is a chronic need, not a fix-and-stop
  • Topical magnesium products — limited transdermal absorption evidence; oral works better

Who should be careful

Women with severe kidney disease may need to limit magnesium intake. Magnesium can interact with some antibiotics and bisphosphonates — space dosing by 2+ hours.

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Frequently asked

For many women, yes — particularly if magnesium-deficient. Effects appear within 1-2 weeks of consistent dosing.

Yes — no significant interactions. Many women on HRT also supplement magnesium.

Serum magnesium poorly reflects total body status (most magnesium is intracellular). RBC magnesium is more accurate but rarely ordered. Most clinicians treat empirically.

Key takeaways

  1. Take 300-400 mg/day of glycinate or citrate (better tolerated, well-absorbed)
  2. Avoid magnesium oxide — high dose appears on the label but absorption is poor (<5%)
  3. Take in the evening — magnesium has a mild sedative effect
  4. Food sources: pumpkin seeds (190 mg/oz), spinach (160 mg/cup cooked), almonds (80 mg/oz), dark chocolate (65 mg/oz)