Why Magnesium and Vitamin D May Be Better Taken Together

Is there really a best time of day to take your vitamins? According to family medicine physician Dr. Rodolfo Perez-Gallardo, timing can make a significant difference when it comes to vitamin and mineral supplements. As he told Cleveland Clinic, “When people don't take vitamins the proper way, they don't see improvement.”

He recommends taking vitamin D, along with other fat-soluble vitamins, after a meal that contains more fat so the body can absorb more of it. A 2010 study in the Journal of Bone and Mineral Research found that after three months of taking vitamin D with their largest meal, 17 vitamin D-deficient participants experienced an improvement of about 50% in their vitamin D levels.

While you are adjusting how you take vitamin D, it may also be worth pairing it with magnesium. The body does not absorb magnesium especially well; on average, only 30% to 40% is absorbed, according to the National Institutes of Health. Still, taking magnesium together with vitamin D may improve how well the body uses both nutrients.

Why vitamin D and magnesium complement each other

When vitamin D is available, the body is able to absorb greater amounts of magnesium. The two nutrients also do not compete for absorption, so one does not gain an advantage at the expense of the other. Here is the connection between magnesium and vitamin D, explained.

A 2013 review in BMC Medicine also found that sufficient magnesium may lower the risk of developing a vitamin D deficiency. More recently, a 2019 review in the American Journal of Therapeutics concluded that magnesium is “essential” for metabolizing vitamin D.

As researcher Dr. Mohammed S. Razzaque, who has studied vitamin D and magnesium, told Doctors of Osteopathic Medicine, “People are taking vitamin D supplements but don't realize how it gets metabolized. Without magnesium, vitamin D is not really useful or safe.”

Additional reasons to take magnesium and vitamin D together

Beyond helping the body absorb more of each nutrient, magnesium and vitamin D may also support broader health goals. One example is bone health. According to Dr. Mohammed S. Razzaque, via Doctors of Osteopathic Medicine, getting enough magnesium and vitamin D can help lower the risk of osteoporosis and bone fractures, respectively. You can also support bone health by learning which foods to include and which to limit.

These nutrients may also have mental health benefits. Speaking with the Cleveland Clinic, psychiatrist Dr. Joseph Austerman said magnesium may help calm overactive neurotransmitters and reduce anxious feelings. “In some ways, magnesium can mimic what some of our anxiety medications do,” he said. Low vitamin D levels have also been linked to anxiety, so getting enough vitamin D and adding magnesium to your diet may help lessen feelings of anxiety and depression.