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Supplementing with vitamin D? Don’t forget about magnesium!

Given the role of vitamin D in how we may respond to the COVID-19 infection, it’s not surprising that vitamin D supplementation has increased in recent months. Vitamin D suppresses the production of antimicrobial peptides in the respiratory track and it might also help to decrease the inflammatory response to the infection, so there are definite benefits to ensuring that your vitamin D levels are optimal.

Two important points to note: It’s always sensible to measure your vitamin D (with a blood test), before starting to supplement. That way you know how much vitamin D to supplement with – some people may need as little as 400 IU vitamin D to maintain healthy levels, whereas others can need as much as 4000 IU a day of vitamin D. Secondly, as nutrients act in a coordinated way paying attention to your magnesium intake will allow you to obtain optimal benefits of vitamin D.

More on magnesium and why it’s essential if you’re supplementing with vitamin D. Firstly, a reminder on good food sources of magnesium. Foods high in magnesium include nuts such as almonds and cashews, seeds, especially pumpkin seeds, bananas, brown rice, beans, leafy greens such as spinach, kale, Swiss chard and dark chocolate. Interestingly, people with diabetes and people who do strenuous exercise lose more magnesium through their urine. Magnesium is especially important for athletes and people with diabetes, as it’s involved in regulating muscle function and blood sugars, in addition to many other essential roles in the body.

It’s easy to forget that nutrients act in a coordinated way, and therefore only to supplement with that nutrient that you need, namely vitamin D in this case. The vitamin D in your supplement needs to be processed further in the liver and kidney to create the active form of vitamin D. This activation process is a magnesium-dependent process. Additionally, the way in which vitamin D is transported in the blood is also a magnesium-dependent process. Research has shown that the effectiveness and clinical benefits of vitamin D are significantly reduced when adequate magnesium levels aren’t maintained. Supplementing with vitamin D without sufficient magnesium means that the body cannot properly metabolise vitamin D, leading to the calcification of blood vessels, which is a risk factor for the development of heart disease. On the other hand, vitamin D has been shown to increase the absorption of magnesium in the gut.

To summerise, if you are supplementing with vitamin D, do not blindly supplement. Get your vitamin D checked to determine whether you need a supplement and the optimal dose required. If you are supplementing with vitamin D ensure that you include magnesium-rich foods in your diet on a daily basis. This is a very good reason to eat a square or two of dark chocolate most days, but don’t forget about leafy greens. Given the fact that a large percentage of the population does not consume adequate magnesium and the safety of magnesium, it may be sensible to supplement with 200 to 400 mg a day of magnesium if you are taking vitamin D. Many multivitamins contain magnesium, but unfortunately the magnesium is in a form that is not well absorbed. Magnesium, in forms such as magnesium glycinate, citrate and malate and better absorbed compared to magnesium oxide.

Supplement wisely.