If you have muscle spasms in your calf, thigh, or feet while you’re sleeping, it can wake you with sharp pain. Around 66% of people ages 50 and older contend with them, adding to sleep problems and daytime fatigue.

It’s often hard to figure out the cause, but risk factors include dehydration, too much or too little exercise, electrolyte imbalances, deficiencies in potassium and magnesium, salt depletion, peripheral vascular disease or peripheral nerve injury, and some medications (ask your doctor about yours).

To help prevent nighttime leg cramps, it’s smart to drink water all day long and consume an 8-ounce bottle of tonic water in the evening. Also, eat foods that supply electrolytes, including almonds, avocados, bananas, oranges, and spinach.

(Electrolytes are minerals such as sodium, potassium, and magnesium that are used by cells to conduct electrical charges throughout the body, including in the muscles.)

Now, a study reveals taking 180 mcg of vitamin K2 daily for eight weeks also tamps down cramps.

Vitamin K is involved in bone health and blood clotting  — and it also impacts release of calcium in cells, muting muscle contraction.

If you’re taking a blood thinner or your doctor advises against taking a supplement, ask if it’s okay to get vitamin K from green leafy vegetables such as spinach, kale, broccoli, and lettuce, as well as vegetable oils, blueberries, figs, and soybeans.