Which Deficiencies Can Cause Leg Cramps?

Original Date of Publication: July 27, 2023

Original Author: Judy Blatman is OmegaQuant’s consumer health writer. Her blogs tee-up practical suggestions for health, with an emphasis on omega-3s and omega-3 testing, so readers can decide their own path to good health. Judy’s knowledge about dietary supplements developed during her 16 years spearheading communications for the Council for Responsible Nutrition, where she led an award-winning healthy lifestyle consumer education initiative focused on diet, dietary supplements and exercise. Learn more

Date of Review/Update: February 20, 2026

Reviewer: Kelly Patterson MS, RD, LDN, CSSD

Kelly Patterson the Clinical Nutrition Educator at OmegaQuant. She is a Registered Dietitian with a background in tactical and sports nutrition. Kelly spent much of her career working for the U.S. Army, including 5 years as a tactical performance dietitian for an elite Special Operations Unit at Fort Bragg, NC. Kelly came to OmegaQuant to further her work on performance biomarkers and to help OmegaQuant expand their testing options. Her work focuses on translating Omega-3 research into practical clinical applications to support performance, resilience, and health. Learn more

 

Have you ever experienced excruciating leg cramps that wake you up in the middle of the night? You’d know if you had, because leg cramps can be incredibly painful as well as disruptive to your sleep. Not to mention that your screams , and perhaps a few shock-and-awe words, would have woken up your sleeping partner too.

Nighttime isn’t the only time you may have experienced leg cramps,  exercise can bring on leg cramping as well. Regardless of when your muscles make their move (or rather, refuse to move at all), there are numerous causes for leg cramps. One which is often overlooked: vitamin or mineral deficiencies.

The Mayo Clinic defines a muscle cramp as a sudden, unexpected tightening of one or more muscles, adding that they take place mostly in the legs, and even more specifically in the calf, that long stretch of back leg muscle that starts below the knee and ends around your ankle.

Sometimes known as a charley horse (for bizarre reasons having to do with baseball), these stubborn muscle occurrences don’t usually last longer than a few minutes and if you’re lucky just a few seconds. What does a leg cramp feel like? A sudden clenching of the muscle, its malleability replaced by a hard tightening that can cause agonizing pain.

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Handling Leg Cramps

What to do? In the immediate, try not to panic or fall out of bed. You can get some relief by rubbing the muscle gently or standing on your legs (if you can), so the muscle cramp will start to stretch out on its own.

The Cleveland Clinic suggests heat, applying a heating pad or a warm bath, or cold, administering an ice pack or ice itself to the area, preferably wrapped in a towel. Then elevate the leg as the cramp pain starts to ease up. Pain medications, ibuprofen or acetaminophen, may also help, but some people have reasons not to take these medications.

Also, not everyone feels pain the same way, so you may need to find your own method. On the bright side, if your leg cramps come from a nutrient deficiency, there’s potentially an easy way to prevent this kind of muscle pain. Keep reading.

As is often the case with anything health-related, some people are more prone to the condition than others. Here are some potential reasons why you may experience leg cramps (1):

• Over-exercising, especially if you are a underconditioned.
• Certain medical conditions, such as: diabetes, multiple sclerosis, kidney disease, Parkinson’s disease, under- or overactive thyroid, high blood pressure
• Pregnancy can bring on muscle cramps, especially if you’re standing on your feet for long periods of time. Oh, the joy!
• Fatigue and lack of sleep, which is kind of ironic given the fact that leg cramps can interrupt your sleep, thereby making you more tired.
• Dehydration robs your muscles of the fluids they need to work properly.
• Not much you can do about that one except eat right, engage regularly in physical activity, reduce stress and get plenty of sleep.

 

Vitamin and Mineral Deficiencies May Cause Muscle Cramps

Vitamins and minerals are necessary for your body to function properly. When you’re not getting enough of the vitamins and minerals you need, the results can be devastating.

Here are three vitamin and mineral deficiencies to avoid if you want to eliminate one potential cause of leg cramps:

 

Vitamin D

There’s no question that vitamin D has its figurative hands in several bodily functions and overall good health, from helping build strong bones and teeth to supporting your immune function. There’s also a growing body of evidence that touts other benefits for vitamin D for heart health, cognitive and mood support, and metabolic function(2).

Further, we know that vitamin D plays a role in muscle health and we’ve blogged before about the growing evidence associating vitamin D deficiency or low levels with chronic and nonspecific musculoskeletal pain, chronic pain, and low back pain as well as muscle weakness, sarcopenia and falls in the elderly. As to whether a vitamin D deficiency can cause leg cramps, the research is mixed.

For example, one small case series observed the association between vitamin D deficiency and concurrent episodes of pain and muscle spasms (3). Although the mechanisms are unclear, it’s been hypothesized that the imbalanced homeostasis of electrolytes, including calcium, magnesium, and phosphorus, resulting from vitamin D deficiency, could lead to muscle dysfunction and potential cramping.

On the other hand, a small study published in the Permanente Journal evaluated whether the correction of vitamin D insufficiency relieved muscle cramps in postmenopausal women(4). The researchers found that vitamin D did not affect the frequency or severity of muscle cramps despite vitamin D repletion. This same study also found no relationship between muscle cramps and dietary or serum magnesium or fluid intake.

Still, some experts consider a lack of vitamin D to be a potential factor in leg cramps.

What is known for sure is this: vitamin D deficiency is a global health concern, with an estimated 1 billion people (adults and children) thought to be vitamin D deficient (5). And that deficiency is relatively easy to find (by testing) and fix (by adding more vitamin D to your diet through dietary supplements).

There are signs of vitamin D deficiency, including fatigue, muscle weakness, back or joint pain, hair loss, headaches, depression and problems sleeping. However, as you will probably recognize, these symptoms are not specific to only a vitamin D deficiency but can also be a sign of other health problems.

Therefore, testing your vitamin D blood levels isthe best way to learn whether you are lacking in this important vitamin. Recommendations from the National Institutes of Health recommend starting life with 400 IU daily of vitamin D, rising to 600 IU at one year, eventually rising to 800 IU for adults 71 years and older. Other experts suggest higher amounts.

At OmegaQuant, we think it’s important to determine how much vitamin D is needed based on how much you already have in your blood. Using your current blood levels as a guide, you can choose the right dose of vitamin D for you.

Beyond adding vitamin D supplements as warranted, other ways to increase your vitamin D blood levels include a doctor-prescribed high dose of vitamin D (for a short period of time), adding vitamin D-rich foods (there aren’t a lot of options, but fatty fish like salmon is a good one) to your diet, and/or increasing your sun exposure (in small doses and with proper sunscreen protection).

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Magnesium Deficiency

Your body needs magnesium for some many critical functions, including energy production and cellular, nerve and muscle function. In addition, some research also shows benefit tohealthy blood sugar regulation, maintaining healthy bones, supporting healthy blood pressure levels, improving sleep and reducing symptoms of stress and anxiety (6).

Your muscles also need magnesium to properly relax, and that’s one reason why a magnesium deficiency may result in leg cramps.

Although the research in this area is new and continuing to evolve, there are some studies showing promise for treatment of leg cramps with magnesium. IFor example, a  2018 randomized, double-blind, placebo-controlled study that showed some promising signs, including a greater reduction of nocturnal leg cramps in the group taking magnesium oxide monohydrate supplements compared to the placebo group (7).

Another small randomized controlled trial  concluded that the mean number of nocturnal leg cramps per week decreased significantly in both the magnesium oxide and placebo groups, albeit with no significant difference between the two (8).

Some early warning signs of magnesium deficiency include nausea, vomiting, lack of appetite, fatigue, and weakness.

You need more than just symptoms to determine a magnesium deficiency. Fortunately, your doctor may order a blood test to check your magnesium levels.  Other tests may also be conducted, including an electrocardiogram (ECG), a calcium blood test (magnesium works in combination with calcium), a comprehensive metabolic panel, a potassium blood test (magnesium also has synergies with potassium), and a urine magnesium test, according to this post.

Once you know where you stand, you can determine with your doctor whether a magnesium supplement could help with your leg cramps. Note that some people are contraindicated for magnesium supplements due to potential interactions with medications.

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Calcium Deficiency

Calcium is best known for building and maintaining strong bones. But the mineral also serves other purposes, like helping your heart, muscles and nerves work properly. A calcium deficiency, also known as hypocalcemia, can have serious long-term consequences, including osteopenia and osteoporosis.

If you’re lacking in calcium, you may not see symptoms early on; therefore, it’s important to be sure you’re getting the recommended amounts of calcium throughout your life, while at the same time, avoiding an overabundance which can lead to other problems.

This fact sheet shares the recommended daily amount of calcium based on age and gender, beginning with 200 mg daily at birth.

According to this article, as your calcium deficiency progresses, different symptoms may appear. For example, with a mild calcium deficiency, you may experience:

• Muscle cramps, including those in your legs
• Brittle nails and dry, scaly skin
• Abnormally (for you) coarse hair

If left untreated, symptoms may progress toinclude neurologic symptoms such as confusion, memory problems, depression and hallucinations, while severe calcium deficiency results in these kinds of symptoms (9):

• Numbness and tingling in the hands, feet, face, lips or tongue
• Muscle spasms in your throat that make breathing difficult
• Seizures
• Heart arrhythmia
• Congestive heart failure

Routine blood tests ordered by your doctor may reveal mild calcium deficiency and at-home blood tests are also available. When your blood serum calcium concentration is less than 8.8 mg/dL, you are considered to have hypocalcemia; severe hypocalcemia, often considered an emergency, is identified at <7 mg/dL.

Your doctor will determine what other tests are necessary to find the cause of your hypocalcemia, including other blood tests to determine your levels of magnesium, phosphorus, parathyroid hormone and/or vitamin D. An EKG and bone imaging tests may also be warranted.

Depending what is causing your calcium deficiency, your doctor may recommend one or more of the following:

• Adding calcium supplements to your diet
• Prescribing an oral calcium medication
• Adding a vitamin D supplement to help with calcium absorption
• Prescribing a synthetic form of parathyroid hormone
• A calcium gluconate IV
• A change in your other medications

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Bottom line: Testing to see if you are lacking in vitamin D, magnesium, or calcium is the best way to potentially eliminate one potential cause of muscle cramps. If you’re not deficient or insufficient, then almost certainly you can eliminate those nutrients as the cause of your muscle cramps.

And if you are low on any of those nutrients, changing your diet or adding a dietary supplement to your daily routine may bring your levels back to sufficiency, potentially helping to reduce or eliminate your leg cramps. Be sure to talk with your doctor or other healthcare practitioner about your individual situation.

References

1. Young G. Leg cramps. BMJ Clin Evid. 2015;2015:1113. Published 2015 May 13.
2. Wimalawansa SJ. Physiological Basis for Using Vitamin D to Improve Health. Biomedicines. 2023;11(6):1542. Published 2023 May 26.
3. ​​Cai C. Treating Vitamin D Deficiency and Insufficiency in Chronic Neck and Back Pain and Muscle Spasm: A Case Series. Perm J. 2019;23:18-241
4. Weiker MK, Nielsen B, Waclawik AJ, Staples AC, Hansen KE. Muscle Cramps Do Not Improve With Correction of Vitamin D Insufficiency. WMJ. 2017;116(5):200-204.
5. Kaur J, Khare S, Sizar O, et al. Vitamin D Deficiency. [Updated 2025 Feb 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan
6. Veronese N, Demurtas J, Pesolillo G, et al. Magnesium and health outcomes: an umbrella review of systematic reviews and meta-analyses of observational and intervention studies. Eur J Nutr. 2020;59(1):263-272.
7. Barna O, Lohoida P, Holovchenko Y, et al. A randomized, double-blind, placebo-controlled, multicenter study assessing the efficacy of magnesium oxide monohydrate in the treatment of nocturnal leg cramps. Nutr J. 2021;20(1):90. Published 2021 Oct 31.
8. Roguin Maor N, Alperin M, Shturman E, et al. Effect of Magnesium Oxide Supplementation on Nocturnal Leg Cramps: A Randomized Clinical Trial. JAMA Intern Med. 2017;177(5):617-623.