Q: I’m having leg cramps when I go to bed and I’d like to take a magnesium supplement to help, but there are so many different kinds. What’s the difference and does it matter which one I take?
Nighttime leg cramps are a common issue, and their frequency tends to increase as we age. Although they are uncomfortable, they are generally harmless but can have a negative impact on sleep. When our sleep is affected often our mood, our ability to concentrate and our productivity become negatively affected as well.
Magnesium is a mineral that plays an important role in many systems that keep our body functioning properly. It helps with energy metabolism, heart rate and blood pressure, blood sugar levels, and a healthy immune system. It also helps our muscles and nerves function properly, and for this reason many people try magnesium supplements to help relieve muscle cramps.
As you’ve pointed out there are many different types of magnesium found in magnesium supplements. I reviewed the medicinal ingredients label on several magnesium products today. Some of them contained only one type of magnesium while others contained two or three different types. I found magnesium oxide, magnesium gluconate, magnesium lactate, magnesium malate, magnesium glycerophosphate, magnesium citrate and magnesium bisglycinate, and this is not a full list of all the types of magnesium.
The difference between each type is what it is bound to. You are always going to find magnesium bound to something else. For example, magnesium citrate is magnesium bound to citric acid and magnesium bisglycinate is magnesium bound to two glycine molecules. What the magnesium is bound to creates differences in how much magnesium is in the supplement, how well our bodies can absorb the magnesium, and it may slightly change what medical conditions the magnesium is used to treat.
Many different types will help with muscle cramping. Magnesium oxide, while very high in magnesium, is not very well absorbed and can have a mild laxative effect. Magnesium citrate is much better absorbed but can also have a mild laxative effect. I usually recommend a supplement containing magnesium bisglycinate as it is very well absorbed by our bodies, and it is gentle on our stomachs. Along with helping reduce muscle cramps, it helps to relax our bodies which can be helpful to promote a restful sleep.
The daily recommended intake of magnesium for adult females is 310 to 360mg and for adult males is 400 to 420mg. It is important to get as much of this from your diet as possible and only use the supplement to top up what you need. When we use food sources to get our magnesium, we also benefit from the other nutrients contained in those foods. Some foods that are good sources of magnesium include spinach, kale, avocado, bananas, almonds, sunflower seeds, oatmeal, whole grains and dark chocolate.
You can help resolve your muscle cramps by ensuring you drink enough water throughout the day as dehydration can trigger leg cramps. Prolonged sitting, frequent standing and walking on hard surfaces such as concrete are also triggers. It is important to keep moving throughout the day, exercise regularly, and ensure you are wearing supportive footwear. Stretching before you go to bed, applying heat to sore muscles, limiting alcohol and caffeine intake, and quitting smoking can all help to prevent muscle cramps from occurring.
If your leg cramps do not resolve within eight weeks of daily use of a magnesium supplement, or at any time become very painful or cause muscle weakness, consult with your primary care provider. You could be suffering from restless leg syndrome which is often described as the sensation of aching, pulling, pins and needles, crawling or tingling in the legs. Restless legs syndrome is sometimes treated with iron supplements if blood work shows your levels are low or prescription medications such as pramipexole or pregabalin.
Check with your pharmacist or primary care provider before starting any new supplements.
Erin Thompson (BSc, BScPharm) is a graduate of Dalhousie University and a community pharmacist practicing at Shoppers Drug Mart in Quispamsis N.B. Her opinions expressed in this column are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment.