Vitamin D
The most important one in this window. Falling estrogen speeds bone loss, and vitamin D — with calcium — is central to protecting your bones, per the NIH Office of Dietary Supplements. Many women are low, especially in northern climates. Ask your clinician to check your level rather than guessing.
Vitamin B12
B12 supports energy and nerve function, and deficiency causes fatigue and brain fog that mimic perimenopause exactly. It becomes more common with age. Easily tested, easily corrected — worth ruling out before blaming everything on hormones.
Magnesium
Technically a mineral, but it belongs on any perimenopause list. It has real evidence for sleep and muscle cramps, and many women run low. Read our deeper guide to magnesium for perimenopause.
Calcium
Important for bones alongside vitamin D — but food-first is best, and supplements only if your intake is genuinely low.
What is usually oversold
Mega-dose menopause multivitamins, biotin for hair, high-dose antioxidants. More is not better — some vitamins are harmful in excess. A targeted approach beats a kitchen-sink pill. For the herbal side (black cohosh, red clover, ashwagandha), see our full supplements guide.
The bottom line
Vitamin D, B12 and magnesium are the evidence-backed core. Test first, treat what is actually low, and skip the mega-multivitamin. See the vitamins guide for detail.
References
- Vitamin D. NIH Office of Dietary Supplements. ods.od.nih.gov
- What Is Menopause? National Institute on Aging. nia.nih.gov