When you’re living with multiple sclerosis (MS), healthy eating can make a real difference by helping your body get the nutrients it needs to manage symptoms and support overall health. Potassium is an essential nutrient your body needs, but it can dip too low in people with MS. Keep reading to learn about the signs of low potassium and how to catch them early.

Several members of the MyMSTeam community have talked about the role of potassium in their lives. After describing their low potassium levels, one MyMSTeam member asked, “What causes low potassium? What foods did you eat to help bring it back up?”

Another member said, “I only started having problems with my potassium when my doctor first suspected I had MS. Are they really related?”

MS is an inflammatory autoimmune disease. The immune system targets and destroys parts of the central nervous system, including the brain and spinal cord. In a process called demyelination, the fatty sheaths (myelin) that protect the nerves deteriorate. This results in a breakdown of communication between the brain and nerves. This breakdown leads to many of the symptoms of MS, including fatigue, vision problems, cognitive decline, and impaired muscle function.

Potassium is a mineral that’s critical for your body to function properly. It’s an electrolyte because it carries a small electrical charge. Your body uses potassium to maintain fluid levels inside cells. Because it carries an electrical charge, potassium also plays an important role in transmitting nerve signals and allowing muscle contraction.

Symptoms of Hypokalemia

Low potassium, known as hypokalemia, occurs when potassium levels in the blood drop below what’s considered normal. Normal levels of potassium vary slightly but can range anywhere from 3.5 to 5.2 millimoles per liter of blood. When levels drop below 2.5 millimoles per liter, it’s considered severe hypokalemia.

If you have low potassium levels, you may experience the following symptoms of potassium deficiency:

• Muscle twitches
• Muscle weakness and cramping
• Paralysis of muscles
• Abnormal heartbeat rhythms
• Constipation
• Fatigue
• Tingling and numbness

You may notice that several of the symptoms of hypokalemia involve muscle function. Muscle problems from low potassium can look a lot like MS symptoms, so it’s not always easy to tell them apart.

Although there’s some overlap between MS and low potassium symptoms, the causes of muscle weakness are different between the two conditions. When you have low potassium, you don’t have enough electrical charge to properly send signals to your nerves. With MS, however, the coating of the nerves is damaged. Although this damage also results in a loss of nerve signaling, it’s not necessarily because you don’t have enough potassium.

Causes of Low Potassium in MS

Many things can cause low potassium levels in the blood. This includes both general and MS-related triggers.

General Causes of Low Potassium

Although not specific to MS, several general factors can contribute to low potassium levels:

• Medications and antibiotics
• Laxatives and diuretics
• Diarrhea and vomiting
• Eating disorders
• Kidney disease
• Excessive sweating
• Hyperaldosteronism (overactive adrenal glands)

Can MS Directly Cause Hypokalemia?

The symptoms of MS and low potassium can be similar. However, it’s unclear if MS can directly lead to lower potassium levels.

Further research is needed to confirm any possible links between MS and potassium levels.

How MS Affects Potassium Levels

Although there’s little evidence to suggest MS directly changes potassium levels, there are many ways MS may indirectly contribute to hypokalemia. For example, medications used to treat MS or symptoms of MS may lead to low levels of potassium.

Corticosteroids, including prednisone and methylprednisolone (Solu-Medrol), are used to treat MS relapses. Side effects of prednisone can include low blood potassium levels. Meanwhile, methylprednisolone can cause increased sweating, which is a general cause of hypokalemia.

Some MS treatments include a class of drugs known as disease-modifying therapies (DMTs). DMTs work by targeting and limiting your immune cells and immune response. Although DMTs effectively slow the progression of MS, they can also put you at an increased risk of infection. Antibiotics used for these infections can lower the levels of potassium in your blood.

According to the Multiple Sclerosis Foundation, people with MS often experience lymphedema (swollen legs and ankles). One way doctors combat this type of fluid buildup is by prescribing diuretics (water pills). Water pills help your body remove excess fluid through urination. By flushing out extra water, diuretics also have the side effect of reducing your potassium levels.

It’s common for people with MS to experience constipation. Laxatives are an easily accessible and relatively safe way to treat constipation. However, laxative overuse has been linked to low potassium levels in the blood.

What Is the Most Common Cause of Low Potassium?

The most common cause of potassium deficiency stems from prescription medication like diuretics. These drugs can make your body lose potassium when you urinate.

People living with MS sometimes take water pills to treat swelling. However, the unwanted side effects of this medication can include low potassium levels.

Managing Low Potassium

If your potassium levels are low, there are several ways to bring your levels back within a normal range.

Dietary Forms of Potassium

Most people get the required amount of potassium through their diets. Many fruits and leafy vegetables are great sources of potassium. Eating the following potassium-rich foods may help manage your low potassium levels:

• Potatoes — Both regular and sweet
• Legumes — Most kinds of beans and lentils
• Leafy greens — Spinach, kale, and Swiss chard
• Fruits — Bananas, dates, prunes, and oranges
• Fruit juices — Particularly orange, prune, and carrot juices
• Seafood — Tuna, salmon, and mackerel
• Dairy — Milk and yogurt
• Others — Tomatoes and avocado are good examples

A healthy diet can provide several benefits, including increased energy, and may also help with your MS symptoms. Remember to talk to a dietitian or your neurologist before making any changes to your diet, as certain foods can interact with prescribed medications.

Nutritional Supplements

If you’re unable to increase your potassium levels through diet alone, you may consider using potassium supplements. These supplements are available over the counter and come in many forms. This includes pills, tablets, powder, liquid, and multivitamins.

If your potassium is low, supplements might help — but it’s safest to take them only with your doctor’s guidance. That’s because excess potassium can pose risks to your health. For example, potassium supplements can lead to too much potassium in the blood, known as hyperkalemia. This can result in muscle cramping, tingling, numbness, and chest pain.

As people get older, the kidneys don’t clear potassium from the body as well as they used to. This means older people are at a higher risk of hyperkalemia if they begin taking supplements. Severe hyperkalemia can be life-threatening.

Some MS medications, such as interferon beta-1a (Avonex) and interferon beta-1b (Betaseron), are risk factors for hyperkalemia. This is because they’ve been associated with high levels of potassium in the blood. People with MS who are using these medications may need to avoid potassium supplements.

Don’t forget to talk to your doctor before starting any new supplements. They’ll be your best resource for understanding how potassium may interact with your current medications and how it may affect your MS. If you begin taking any supplements, be sure to follow up with your doctor regularly to monitor your potassium levels.

Join The Conversation

On MyMSTeam, people share their experiences with multiple sclerosis, get advice, and find support from others who understand.

Do you have hypokalemia, or are you curious about how potassium levels might affect your MS? Share your thoughts in the comments below.