Mineral Supplementation on a Keto Diet Is It Necessary?
Contrary to conventional thinking, keto diets can be very healthy.
Meat, fish, eggs, dairy, nuts and vegetables are rich in several key nutrients that your body needs on a daily basis.
For most people following a well-balanced keto diet, a vitamin supplement usually isn’t necessary. However, in some cases, supplementing with minerals known as electrolytes may be beneficial because your body processes them differently when carb intake is very low, as discussed in this paper by Dr. Steve Phinney, one of the foremost experts in ketogenic diets.
- Nutritional ketosis: effect on electrolytes
- Is mineral supplementation necessary on a keto diet?
- What about exogenous ketone supplements?
1. Nutritional ketosis: effect on electrolytes
According to many health organizations, most people should cut back on sodium in order to prevent high blood pressure and other health problems. On high-carb diets, this might be true. However, on a keto diet, your sodium needs actually increase.
When carb intake is dramatically reduced, blood insulin levels decrease. A 2007 review by Tiwari, et al, suggested that under conditions of low insulin, the kidneys absorb less sodium and excrete more into the urine. However, according to Dr. Phinney, the precise reason for increased sodium loss during ketosis appears more complex and isn’t completely understood. Regardless of the mechanism responsible for this effect, if sodium isn’t replaced, you may experience fatigue, weakness, dizziness, headaches, and difficulty concentrating.
Moreover, when your body loses sodium, your kidneys increase potassium excretion in an attempt to maintain balance. Symptoms of low potassium levels include muscle cramps, muscle twitching, and heart palpitations, or an increased awareness of your heartbeat.
Although many of these side effects are especially noticeable in the first week or two of starting a keto diet (often referred to as “keto flu”), they may continue indefinitely if sodium and potassium levels remain suboptimal.
Whether sodium and potassium reabsorption by the kidneys returns to baseline following keto-adaptation isn’t entirely clear.
For instance, a 2002 study by Westman and colleagues reported a reduction in blood sodium levels in obese people 6 months after following a diet containing 25 grams of carb per day.
On the other hand, an earlier study by Rabast, et al, found that although sodium and potassium excretion increased during the initial stage of a low-carb diet, this effect was no longer seen after 28 days.
Therefore, it’s difficult to say with certainty whether sodium and potassium needs remain higher on a ketogenic diet in the long term.
Magnesium deficiency is also fairly common and may be the culprit behind frequent muscle cramps at night or after exercising. Although muscle cramps can also occur with inadequate potassium, sodium, or fluid intake, getting too little magnesium is a very common cause.
Unlike sodium and potassium, magnesium needs aren’t increased on a keto diet. However, many people don’t get enough magnesium from diet alone.
2. Is mineral supplementation necessary on a keto diet?
The decision to take mineral supplements should be based on the foods you eat and how physically active you are. If you engage in endurance exercise or any type of rigorous physical activity, you may find it difficult to get enough electrolytes solely from food.
Here are the daily mineral needs for people who follow a keto lifestyle, the best keto-friendly food sources, and supplement recommendations for those who can’t meet their needs through diet alone.
Daily need: 3,000-7,000 mg
Most people get at least 2,000 mg of sodium from the foods they eat. You can increase the amount you get at meals by adding salt, which provides 2,300 mg of sodium per teaspoon. Another strategy is to drink broth, which contains about 1000 mg of sodium per cup.
Note: If you have high blood pressure, heart failure, or kidney disease, be sure to speak with your doctor before increasing your sodium intake.
Although most foods contain only low to modest amounts of potassium, there are several low-carb sources that can help you meet your daily requirement:
Keto-friendly high-potassium foods
- Avocado: 1,000 mg per medium avocado (200 grams)
- Swiss chard, cooked: 950 mg per cup (175 grams)
- Spinach, cooked: 840 mg per cup (180 grams)
- Mushrooms, cooked: 550 mg per cup (150 grams)
- Brussels sprouts: 500 mg per cup (160 grams)
- Salmon: 430-500 mg per 4 ounces (114 grams)
- Broccoli, cooked: 460 mg per cup (160 grams)
- Flounder: 400 mg per 4 ounces (114 grams)
- Artichoke: 345 mg per medium artichoke (120 grams)
- Almonds: 200 mg per ounce (30 grams)
Although getting potassium from your diet is preferable, if you are very active or don’t consume enough potassium-rich food on a regular basis, it may make sense to take supplemental potassium on an as-needed basis.
Potassium supplements are typically available as 99 mg tablets. This is because your blood potassium levels need to remain within a narrow range, and taking too much in concentrated form can be dangerous, especially for those who take certain medications.
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. Taking up to 1000 mg of supplemental potassium per day should be safe for most people who aren’t able to meet their needs through food alone.
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.
Daily need: 400 mg
Most foods only contain small amounts of magnesium, but there are a few good sources that can be included on a keto-diet. What’s more, many of them are high in potassium as well.
Keto-friendly high-magnesium foods
- Swiss chard, cooked: 150 mg per cup (175 grams)
- Pumpkin seeds, dried: 150 mg per ounce (30 grams)
- Mackerel: 105 mg per 4 ounces (114 grams)
- Chia seeds: 95 mg per ounce (30 grams)
- Dark chocolate (70-85% cacao): 70-90 mg per ounce (30 grams)
- Almonds: 75 mg per ounce (30 grams)
- Spinach, cooked: 75 mg per cup (180 grams)
- Pine nuts: 70 mg per ounce (30 grams)
- Avocado: 60 mg per medium avocado (200 grams)
- Artichoke: 50 mg per medium artichoke (120 grams)
Taking up to 400 mg of magnesium 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. In addition, magnesium glycinate and Slow-Mag (a slow-digesting form of magnesium chloride) seem least likely to cause loose stools or other digestive problems.
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.
3. What about exogenous ketone supplements?
Endogenous ketones are produced by your liver when insulin and blood sugar levels are low. By contrast, exogenous ketones are supplements that are ingested.
Ketones salts consist of β-hydroxybutyrate bound to a mineral salt like calcium, magnesium, potassium or sodium. There are several brands of ketone salts that are widely available for purchase online and through independent distributors.
Ketone esters consist of β-hydroxybutyrate that is bound to another compound instead of a mineral salt. Ketone esters are used primarily in research and are not available commercially at this time.
Several animal studies suggest that ketone esters may be helpful for certain types of cancer, brain injury, and other neurological conditions. In addition, there’s emerging evidence supporting their use in improving physical performance. Although these results are encouraging, it’s important to recognize that high-quality human research on exogenous ketones has yet to be done.
Moreover, there’s no evidence suggesting that ketone supplementation promotes weight loss. Indeed, taking exogenous ketones will increase your total calorie intake for the day. In addition, some people have reported side effects when taking ketone supplements, such as increased urination and large fluctuations in appetite. Finally, there’s no denying that they are quite expensive and have an unpleasant taste.
On the other hand, by simply following a well-balanced ketogenic diet based on real food, you can get all the benefits of ketosis naturally, pleasurably, and without spending a lot of money.
In summary, to feel and perform your best on a keto diet, make sure to consume plenty of electrolyte-rich foods, and supplement with minerals in appropriate amounts, if needed.