What is magnesium?
Magnesium is an essential mineral; the adult body holds about 25 g, mostly in bone. It helps make ATP, build protein and DNA, contract and relax muscles, send nerve signals, and regulate blood sugar and blood pressure (NIH, 2022).
What happens if you don't get enough?
Early signs are vague—loss of appetite, fatigue, nausea. More severe deficiency can cause muscle cramps, tingling and abnormal heart rhythms. National surveys suggest many Americans eat less than the recommended amount (Rosanoff et al., 2012), though true deficiency is less common. Heavy drinking, type 2 diabetes, and long-term diuretics or acid reflux drugs (PPIs) raise the risk.
How much do you need, and are supplements safe?
The US RDA is 400–420 mg a day for men and 310–320 mg for women. An ounce of pumpkin seeds has about 156 mg; an ounce of almonds about 80 mg. Supplements come as magnesium oxide, citrate, glycinate and others. The upper limit from supplements is 350 mg a day—beyond that, diarrhea is common. People with kidney disease should talk to a doctor first. Evidence for better sleep or migraine prevention is promising but limited.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Which form of magnesium is best?
- Citrate and glycinate are generally better absorbed than oxide; oxide and citrate are more likely to loosen stools.
- Can magnesium help with sleep?
- A few small studies in older adults found modest benefits, but the evidence is mixed. Ongoing insomnia deserves a proper evaluation.
Sources reviewed: 2026-10-25
References
- National Institutes of Health, Office of Dietary Supplements. (2022). Magnesium: Fact sheet for health professionals. NIH.
- 보건복지부·한국영양학회. (2020). 2020 한국인 영양소 섭취기준. 보건복지부.
- Rosanoff, A., Weaver, C. M., & Rude, R. K. (2012). Suboptimal magnesium status in the United States: Are the health consequences underestimated? Nutrition Reviews, 70(3), 153–164.