Magnesium
What it is and what it does
- An adult body contains about 25 g of magnesium; 50-60% is in bone and most of the rest in soft tissues. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals (updated 2026-01-06))
- Magnesium is a nutrient the body needs to stay healthy. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- Magnesium is a helper (cofactor) for more than 300 enzyme systems in the body. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals (updated 2026-01-06))
- It helps regulate muscle and nerve function, blood sugar and blood pressure, and is used to make protein, bone and DNA. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- Magnesium is required for energy production. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals (updated 2026-01-06))
- It helps move calcium and potassium across cell membranes, which matters for nerve signals, muscle contraction and a normal heart rhythm. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals (updated 2026-01-06))
Why it matters
- In the short term, low magnesium intake does not cause obvious symptoms. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- Symptoms of magnesium deficiency include loss of appetite, nausea, vomiting, fatigue and weakness. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- Severe deficiency can cause numbness, tingling, muscle cramps, seizures, personality changes and abnormal heart rhythm. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- Too much: magnesium naturally present in food and drinks is not harmful and does not need to be limited. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- High doses from supplements or medicines can cause diarrhoea, nausea and abdominal cramping. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
General information, not medical advice — for your own needs, ask a doctor or dietitian.
How much is needed
| Who | Amount | What the figure is | Whose figure |
|---|---|---|---|
| Adult man, sedentary work | 440 mg/day | recommended dietary allowance | ICMR-NIN 2020 |
| Adult woman, sedentary work | 370 mg/day | recommended dietary allowance | ICMR-NIN 2020 |
| Pregnant woman | 440 mg/day | recommended dietary allowance | ICMR-NIN 2020 |
| Adult men and women (and pregnancy where stated) | 350 mg/day | safe upper limit | ICMR-NIN 2020 |
Sources: ICMR-NIN Nutrient Requirements for Indians 2020, as given by FSSAI (Direction of 2 Aug 2021); ICMR-NIN Nutrient Requirements for Indians 2020 (Short Report)
In every millet and pseudo-cereal, per 100 g raw
| Grain | Amount | Source |
|---|---|---|
| Fonio | 430 mg | FAO WAFCT 2019 |
| Rajgira (amaranth) | 270 mg | IFCT A002 |
| Kuttu (buckwheat) | 231 mg | USDA FDC 170286 |
| Teff | 184 mg | USDA FDC 169747 |
| Ragi (finger millet) | 146 mg | IFCT A010 |
| Jowar (sorghum) | 133 mg | IFCT A005 |
| Bajra (pearl millet) | 124 mg | IFCT A003 |
| Kodo millet | 122 mg | IFCT A017 |
| Quinoa | 119 mg | IFCT A009 |
| Proso millet | 114 mg | USDA FDC 169702 |
| Little millet | 91.41 mg | IFCT A016 |
| Barnyard millet | 82 mg | NIN 2007 via ICAR-IIMR |
| Foxtail millet | 81 mg | NIN 2007 via ICAR-IIMR |
Each grain has ONE source, named on its page: IFCT = Indian Food Composition Tables 2017 (ICMR-NIN) with its food code; USDA FDC; FAO WAFCT 2019; NIN 2007 via ICAR-IIMR. Values exactly as printed, not converted — tables differ in method, so compare within a source. Published values for the grain, not a laboratory test of our packs.
Absorption and food
- About 30-40% of the magnesium in food is absorbed. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals (updated 2026-01-06))
- ICMR-NIN assumed about 40% absorption when setting the Indian requirement. (ICMR-NIN Expert Group. Short Report of Nutrient Requirements for Indians: Recommended Dietary Allowances and Estimated Average Requirements - 2020)
- When intake is low, healthy kidneys hold back magnesium by passing less into urine. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- Very high supplemental zinc (142 mg/day) can interfere with magnesium absorption. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals (updated 2026-01-06))
- Phytic acid in cereals and pulses hinders mineral absorption; boiling or pressure-cooking lowers it considerably, making iron, calcium, magnesium and zinc more absorbable. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- Legumes, nuts, seeds, whole grains and green leafy vegetables provide magnesium. (NIH Office of Dietary Supplements. Magnesium Fact Sheet for Consumers (updated 2021-03-22))
- Food-group averages per 100 g raw (ICMR-NIN): nuts 185.6 mg, dry spices 160.1 mg, pulses 133.3 mg, millets 73.9 mg, cereals 69.1 mg magnesium. Group averages only. (ICMR-NIN. Dietary Guidelines for Indians 2024)