Phytate-rich foods, such as tea and beans, high doses of zinc or vitamin D from supplements, smoking, drinking too much alcohol, certain diseases and aging can inhibit magnesium absorption.
Nuts & beans may inhibit the absorption of magnesium
Above all, certain compounds in plant-based foods, such as cellulose and phytate can inhibit the absorption of magnesium. Cellulose is a type of insoluble fiber. Phytate or phytic acid is an anti-nutrient compound.[1]
As a rule of thumb, avoid taking magnesium supplements with vegetables, legumes, whole grains, nuts, seeds. and fruits, as these foods are high in cellulose and phytate. Green tea and dark coffee are also high in phytate.
However, you can decrease the phytate content of beans and nuts by soaking them. Soaking and rinsing beans and nuts significantly improves the absorption rate of magnesium as well as other minerals.
So, you could soak almonds. Actually, almonds are the richest nuts in magnesium!
Zinc & vitamin D supplements may cause magnesium depletion
Also, too much zinc can interfere with magnesium absorption and disrupt the magnesium balance in the body. However, we have to get extremely high dosages of zinc (142 mg per day) to inhibit magnesium absorption. We can get these amounts only from dietary supplements, or consuming too many oysters. Healthy people can’t possibly consume too much zinc from food.[2]
Furthermore, long-term high dosages of vitamin D from supplements can induce severe depletion of magnesium. Therefore, if you take vitamin D supplements, you should regularly check your vitamin D levels.[3]
However, we should have normal vitamin D levels for optimal absorption of magnesium. In fact, vitamin D at normal levels may enhance magnesium absorption. However, as vitamin D deficiency is pretty common, many people would benefit from taking high amounts of vitamin D from dietary supplements.[4]
Smoking, alcohol & drugs are bad for magnesium absorption
Moreover, cigarette smoking can also cause magnesium deficiency. First, smoking may cause decreased appetite. Thus, smokers get less magnesium from food. Moreover, smoking may cause disturbances in the functions of the digestive system, reducing magnesium absorption as well as other minerals.[5]
Chronic alcoholism, certain health conditions, and certain medication can lead to magnesium deficiency as well.
Aging also increases the risk of magnesium deficiency. Magnesium absorption from the gut decreases with age, while renal magnesium excretion increases! Furthermore, elderly people are more likely to have chronic diseases or take medications that negatively affect the magnesium status of the body.
