Magnesium is arguably one of the most important and essential minerals in the body, which is why deficiencies cause serious and sometimes debilitating side effects. It is required for cellular health and is a critical component of over 300 biochemical functions in the body. Deficiencies can be due to several dietary or medical reasons, but research also shows that certain genetic variants can also contribute to magnesium deficiencies.
What functions does magnesium have in the body?
The adult body contains approximately 25 g of magnesium, with 50% to 60% present in the bones and soft tissues. It contributes to several processes and structures in the body which include:
- The structural development of bone
- Synthesis of DNA, RNA, and the antioxidant glutathione
- Transport of calcium and potassium ions across cell membranes
- Nerve impulse conduction
- Muscle contraction
- Normal heart rhythm
Are we getting enough magnesium through our diets?
The results of dietary surveys that have been conducted on people in the United States consistently show that a large majority of people consume less than the recommended amounts of magnesium per day.
An analysis of data from the National Health and Nutrition Examination Survey (NHANES) of 2013-2016 found that 48% of Americans of all ages ingest less magnesium from food and beverages than their respective expected average requirement1. Specifically, adult men aged 71 years and older and adolescent males and females are most likely to have a low daily intake of magnesium.
Magnesium 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).
These are foods that contain the highest amount of magnesium per serving:
- Pumpkin seeds, roasted, 1 ounce- 156mg
- Chia seeds, 1 ounce – 111mg
- Almonds, dry roasted, 1 ounce – 80mg
- Spinach, boiled, ½ cup – 78mg
- Cashews, dry roasted, 1 ounce – 74mg
- Peanuts, oil roasted, ¼ cup – 63mg
- Cereal, shredded wheat, 2 large biscuits – 61mg
- Soymilk, plain or vanilla, 1 cup – 61mg
- Black beans, cooked, ½ cup – 60mg
- Edamame, shelled, cooked, ½ cup – 50mg
Magnesium levels are largely controlled by the kidney, which typically excretes about 120 mg of magnesium into the urine each day. The chance of experiencing serious adverse effects from ingesting too much magnesium is therefore unlikely since your kidneys do a great job filtering out excess magnesium, however, in doses higher than 600 mg, diarrhea may occur. The risk of magnesium toxicity does however increase with impaired kidney function.
Symptomatic magnesium deficiency due to low dietary intake in otherwise-healthy people is uncommon because your kidneys can also limit urinary excretion of mineral levels that are low in the body. However, habitually low intakes or excessive losses of magnesium due to certain health conditions, chronic alcoholism, and/or the use of certain medications can lead to magnesium deficiency.
Early signs of magnesium deficiency include:
- Loss of appetite
- Nausea and/or vomiting
If the magnesium deficiency persists, symptoms may become more severe:
- Muscle contractions and cramps
- Personality changes
- Abnormal heart rhythms
- Coronary (heart muscle) spasms
Are You at Risk for Magnesium Deficiency?
Can one person be more susceptible to a magnesium deficiency than another? According to the National Institute of Health, not everyone is created equal concerning metabolizing and assimilating magnesium. In fact, certain people are inherently at a greater risk of developing a magnesium deficiency.
The following genes impact magnesium levels and metabolism.
The TRPM6 gene encodes a subunit of an ion channel that is involved in magnesium uptake in the kidney. The T allele of the SNP in TRPM6 that is found in approximately 92% of Americans increases the risk for hypomagnesemia by 20%2.
SNPs in the ATP2B1 gene have also been associated with altered magnesium levels and a risk for hypomagnesemia. The ATP2B1 gene has an indirect effect on blood magnesium levels via its function in calcium homeostasis regulation. The G allele of the SNP in the ATP2B1 that is found in 29% of the general population increases risk by 24% 3.
The CASR gene contains instructions for producing a protein called the Calcium Sensing Receptor. The CASR protein mainly regulates calcium levels but also influences the reabsorption of magnesium in the kidneys4. The G allele of the SNP was associated with higher serum magnesium levels 5.
Soil depletion affects magnesium levels
Magnesium used to be abundantly present in most foods, especially before the 1970s. However, in recent years, food has less and less magnesium and other essential minerals and vitamins due to the farming practices and changes in growing cycles over the last century6.
The benefits of increasing yield by farmers to supply food for expanding populations outweigh small nutrient dilution effects which have been addressed by eating the recommended daily servings of vegetables, fruits, and whole grains.
A report published by the Kushi Institute analyzed nutrient data from 1975 to 1997 and found that the average calcium levels in 12 fresh vegetables dropped 27 percent, iron levels by 37 percent, vitamin A levels by 21 percent, and vitamin C levels by 30 percent.
So even if you eat a completely organic, non-GMO raw food diet, you’re still at risk of deficiency because of soil depletion and the current capitalistic farming practices.
Should you take a magnesium supplement?
If you feel that you lack sufficient intake of magnesium in your diet, you may want to consider magnesium supplementation.
Research has shown that by ingesting the recommended daily intake of magnesium, especially through supplementation, bone health and osteoporosis prevention and management are greatly improved. It also decreases inflammatory markers, which decreases the risk for chronic health conditions such as type 2 diabetes, heart disease, and certain cancers.
As mentioned earlier, one of the main roles of magnesium is to ensure proper neuron functioning. Therefore, magnesium deficiency can cause neurological complications. Migraine is usually related to low amounts of magnesium in the serum and cerebrospinal fluid, and it has been proposed that magnesium supplementation can reduce migraine intensity and frequency7.
What form of magnesium should you supplement with?
Any of the forms of magnesium below ensure maximal absorption and bioavailability:
- Magnesium Threonate
- Magnesium Chelate
- Magnesium Chloride Oil
- Magnesium Citrate
- Magnesium Glycinate
The bottom line: getting enough magnesium is essential for maintaining good health because, without it, your body can’t function optimally.