Listed as one of the even essential macrominerals, magnesium is one of the minerals that people need to consume in relatively large amounts — at least 100 milligrams (mg) per day. It is an abundant mineral in the body and is naturally present in many foods, added to other food products, available as a dietary supplement, and present in some medicines (such as antacids and laxatives).
Magnesium is a cofactor in more than 300 enzyme systems that regulate diverse biochemical reactions in the body, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium is required for energy production, oxidative phosphorylation, and glycolysis. It contributes to the structural development of bone and is required for the synthesis of DNA, RNA, and the antioxidant glutathione. Magnesium also plays a role in the active transport of calcium and potassium ions across cell membranes, a process that is important to nerve impulse conduction, muscle contraction, and normal heart rhythm.
How should magnesium be taken?
The recommended dietary allowance (RDA) includes the magnesium you get from both the food you eat and any supplements you take.
| Category | Recommended Dietary Allowance (RDA) |
| CHILDREN | |
| 1-3 years | 80 mg/day |
| 4-8 years | 130 mg/day |
| 9-13 years | 240 mg/day |
| FEMALES | |
| 14-18 years | 360 mg/day |
| 19-30 years | 310 mg/day |
| 31 years and over | 320 mg/day |
| Pregnant | Under 19 years: 400 mg/day 19 to 30 years: 350 mg/day 31 years and up: 360 mg/day |
| Breastfeeding | Under 19 years: 360 mg/day 19 to 30 years: 310 mg/day 31 years and up: 320 mg/day |
| MALES | |
| 14-18 years | 410 mg/day |
| 19-30 years | 400 mg/day |
| 31 years and up | 420 mg/day |
The Tolerable Upper Intake Level is the maximum daily intake unlikely to cause harmful effects on health. The UL for magnesium is 350 milligrams from supplements only. High-dose supplements can lead to diarrhea, nausea, and cramping in some people.
Extra magnesium from food is safe because the kidneys will eliminate excess amounts in urine. An adult body contains approximately 25 g magnesium, with 50% to 60% present in the bones and most of the rest in soft tissues. Less than 1% of total magnesium is in blood serum, and these levels are kept under tight control. Normal serum magnesium concentrations range between 0.75 and 0.95 millimoles (mmol)/L. Hypomagnesemia is defined as a serum magnesium level less than 0.75 mmol/L.
Why is magnesium taken at night?
Experts recommend taking magnesium at night because of its ability to improve sleep. Studies have shown that taking 500 mg of magnesium daily can improve the quality of sleep.
Good sleep is part of good quality of life and the relationship between sleep and overall physical health is well-documented. Sleep allows both the body and brain to recover during the night. A good night’s rest ensures you’ll feel refreshed and alert when you wake up in the morning.
Magnesium also plays an important role in the nervous system, helping to activate mechanisms that quiet and calm a person. It may also help relieve anxiety and depression, which can interfere with sleep.
However, the only research currently showing that magnesium supplements improve sleep were been done in older adults, so it’s not clear how they affect other populations.
You may also find useful information on Can You Take Magnesium While Taking Losartan?
