Do you need electrolyte supplementation on a low-carb or keto diet?

It’s becoming more widely accepted that low-carb and ketogenic diets can be healthy and nutritionally complete.¹ Meat, fish, eggs, dairy, nuts and vegetables are rich in key nutrients that your body needs on a daily basis. In some cases, however, supplementing with minerals known as electrolytes may be beneficial.

This is because when carb intake is extremely low, levels of electrolytes – especially sodium  – can drop. And if this happens, you may not feel your best.²

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Symptoms of electrolyte deficiency and what to do about them

Interested in learning more about why electrolyte levels can decrease on low carb and other dietary options to replenish them? Keep reading!

Sodium

According to many health organizations, most of us should be cutting back on sodium in order to prevent high blood pressure and other health problems. For example, The American Heart Association recommends consuming less than 2.3 grams and ideally no more than 1.5 grams of sodium per day.

For people with hypertension and insulin resistance who eat high-carb diets, this advice might be warranted. However, multiple meta-analyses of RCTs have shown a small blood pressure lowering effect without clear evidence of improved overall health.¹² 

And many observational studies suggest that the optimal sodium intake is between 3 and 6 grams per day.¹³ In addition, on a low-carb or keto diet, your sodium needs may actually increase, due to increased losses via the kidneys.¹⁴ In this situation, we are therefore usually more concerned with too little sodium rather than too much.

Symptoms of deficiency

• Fatigue
• Weakness
• Headaches
• Difficulty concentrating¹⁵

Add salt to your diet

Daily need: Most people on a low-carb diet will likely feel best with 3–7 grams of sodium (7–17 grams of salt, or about 1-3 teaspoons) per day.¹⁶¹⁷

However, if you have certain medical conditions — such as hypertension, kidney disease, or congestive heart failure — you may need to be more cautious about sodium. Read our complete guide on salt to learn why optimal intake varies from person to person.

Most people get at least 2 grams of sodium from the foods they eat. You can add a teaspoon of salt to a liter of water and drink it over the course of the day. Another strategy is to drink broth or bouillon, which contains about 1 gram of sodium per cup.

If you do physical exercise, adding sodium prior to a workout may improve your performance. Drs. Phinney and Volek recommend taking one-half teaspoon of salt within the half hour prior to exercising in their book The Art and Science of Low Carb Performance.¹⁸

Note: If you have high blood pressure, heart failure, or kidney disease, be sure to speak with your doctor before increasing your sodium intake.

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Potassium

It is estimated that, as a population, we typically consume less than half the recommended amount of potassium.¹⁹ Therefore, it is even more important to optimize intake of this essential nutrient, which can be lost during low-carb or keto eating.

As sodium loss in the urine increases during the initial phase of a low-carb or keto diet, the kidneys may respond by trying to reabsorb sodium. Unfortunately, that process comes at the expense of losing potassium, a process that maintains biochemical balance.²⁰

Symptoms of deficiency

• Muscle cramps
• Muscle twitching
• Heart palpitations/Increased awareness of heartbeat²¹

High-potassium foods

Daily need: 3,000–4,700 mg (3–4.7 g) of potassium

To get more potassium into your diet, you could take potassium supplements. Or, why not try adding an avocado or a couple of servings of other low-carb-friendly high-potassium foods to your diet on a daily basis?

1. Avocado 1,000 mg per large avocado (200 grams)
2. Swiss chard, cooked 950 mg per cup (175 grams)
3. Spinach, cooked 840 mg per cup (180 grams)
4. Mushrooms, cooked 550 mg per cup (150 grams)
5. Brussels sprouts: 500 mg per cup (160 grams)
6. Broccoli, cooked 460 mg per cup (160 grams)
7. Salmon 430–500 mg per 4 ounces (114 grams)
8. Meat 400–500 mg per 4 ounces (114 grams)
9. Flounder 400 mg per 4 ounces (114 grams)
10. Artichoke 345 mg per medium artichoke (121 grams)
11. Hemp seeds 335 mg per ounce (30 grams)
12. Almonds 200 mg per ounce (30 grams)

Supplements

If you’re very active or don’t consume enough potassium-rich food on a regular basis, it might make sense to take supplemental potassium on an as-needed basis.

Potassium supplements are typically available as 99 mg tablets.²² Note that although the front label on a potassium supplement may list 595 mg as the dosage, each tablet only contains 99 mg of pure potassium, which can be verified on the detailed “Supplement Facts” label on the back of the container.

Your blood potassium levels need to remain within a narrow range, and taking too much in concentrated form can be dangerous, especially if you take certain medications or have kidney disease. For this reason, it’s best to get your potassium through food intake whenever possible.

Note: If you have high blood pressure, heart disease, kidney disease, or are taking medications for any other condition, be sure to speak with your doctor before you take a potassium supplement.

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Magnesium

Although magnesium is found in a wide variety of foods, many people don’t get enough from diet alone. In fact, it’s estimated that almost 50 percent of the US population does not meet the daily dietary requirement for magnesium.²³

Symptoms of deficiency

Symptoms of magnesium deficiency may include muscle twitching or cramping at night or after exercising. Although muscle cramps can also occur with inadequate potassium, sodium, or fluid intake, getting too little magnesium can be a common cause.²⁴

High-magnesium foods

Daily need: 400 mg magnesium

Most foods don’t provide much magnesium, but there are a few good sources that can be included on a low-carb or keto diet. What’s more, many of them are high in potassium as well. Eating Swiss chard and other cooked greens on a regular basis is a great strategy for helping to meet your magnesium needs.

1. Hemp seeds 195 mg per ounce (30 grams)
2. Swiss chard, cooked 150 mg per cup (175 grams)
3. Pumpkin seeds, dried 150 mg per ounce (30 grams)
4. Mackerel 105 mg per 4 ounces (114 grams)
5. Chia seeds 95 mg per ounce (30 grams)
6. Dark chocolate (70–85% cacao) 70–90 mg per ounce (30 grams)
7. Almonds 75 mg per ounce (30 grams)
8. Spinach, cooked 75 mg per cup (180 grams)
9. Pine nuts 70 mg per ounce (30 grams)
10. Avocado 60 mg per large avocado (200 grams)
11. Artichoke 50 mg per medium artichoke (120 grams)

Supplements

Taking up to 400 mg of magnesium per day in supplement form is safe for most people with healthy kidneys. Some forms of magnesium can cause digestive issues, however, especially when taken alone. For this reason, it’s best to take a magnesium supplement with a meal.

Forms that are well absorbed include magnesium citrate, magnesium chloride, and magnesium glycinate (also known as magnesium bisglycinate or diglycinate).²⁵ Additionally, magnesium glycinate and Slow-Mag (a slow-digesting form of magnesium chloride) seem least likely to cause loose stools or other digestive issues.²⁶

Note: If you have kidney disease, you may not be able to handle a large amount of magnesium. In addition, certain medications may interact negatively with magnesium supplements. Speak with your doctor before taking a magnesium supplement if any of these apply to you.

Conclusion

So, in the end, do you need to take supplements on a keto or low-carb diet? Probably not. You can likely pick and choose your favorites from all the foods listed in this guide to meet your requirements. But, if you don’t like many of these foods; find it difficult to eat enough to get the minimum recommended amounts of minerals; or if you exercise regularly and have excessive loss of electrolytes, then you may want to consider supplementation.

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