Q: "I've been told by friends that I need to take magnesium tablets to get rid of the cramp I've been getting in my calves at night. Can you tell me what foods contain magnesium, as I'd rather make diet changes than take pills if possible."Ann
A: Nutritionist Amanda Johnson responds:
"Muscle cramps are very common, in fact most of us have probably experienced cramps at some point in our lives. There are different causes of cramp, eg. injury, vigorous activity and muscle fatigue. Cramps may also occur at night (rest cramps), the actual cause of such cramps is unknown.
Magnesium deficiency may result in cramps; however deficiency occurs rarely in humans unless low intakes are accompanied by prolonged diarrhoea and excessive urinary losses. If you do want to increase your intake of foods containing magnesium, most green vegetables, legumes, peas, beans and nuts are good sources. Magnesium is widely distributed in both plant and animal foods.
There is no guarantee that dietary changes will cure this problem, but there are some modifications you may wish to consider. As cramps can commonly occur during dehydration, it is important to drink plenty of fluids before, during and after exercise. In terms of nutrients, calcium plays an essential role in muscle contractions, so ensuring an adequate calcium intake may be helpful, eg. by including low-fat dairy products such as yoghurt and cheese in the diet.
A lack of potassium may also play a role in muscle cramps, so it certainly won't hurt to ensure you get lots of potassium-rich foods like fruits and vegetables in the diet. Excessive intakes of sodium are inadvisable as this is linked to high blood pressure, however if you are losing a significant amount of sodium through sweat (as a result of high levels of activity such as endurance exercise), having a little salt in the diet may be appropriate.
It may also be useful to consult with a physiotherapist about appropriate stretching exercises."