If we had to pinpoint one particular “flaw” about the keto diet, it’s that it can be tough for people to meet their micronutrient needs.

The more common micronutrient deficiencies on keto are generally the following:

  1. Calcium deficiency
  2. Magnesium deficiency
  3. Potassium deficiency

Coincidentally, these are all mineral electrolytes.

Vitamin deficiency tends to be uncommon on the keto diet since you should be eating a generous amount of vegetables and fatty foods. Theoretically, this should be covering all your bases for water-soluble and fat-soluble vitamins.

The good news?

You can remedy any micronutrient deficiencies on keto fairly easily, with or without a nutritional supplement like a multivitamin.

What Exactly Are Micronutrients?

In human nutrition, we typically divide nutrients into two broad categories:

  1. Macronutrients
  2. Micronutrients

Macronutrients are substances that our body needs in relatively large quantities for healthy function and survival.

Micronutrients, on the contrary, are substances that our body needs in relatively small quantities for healthy function and survival.

Many people overlook the importance of micronutrients in their diet, especially those on keto.

While overall energy and macronutrient intake are the most important factors in health and well-being, micronutrient intake is a close second.

In fact, micronutrient deficiencies can cause a variety of symptoms and health complications if left untreated.

For example, hypomagnesia (magnesium deficiency) can bring about lethargy, cognitive impairment, constipation, anxiety, and a host of other unwelcome ramifications.

Sadly, research shows that magnesium deficiency is a growing health concern since many plants are losing their natural magnesium content.

As such, the main concern for many keto dieters is figuring out how to avoid micronutrient deficiencies and what the best low-carb sources are for magnesium, calcium, and potassium.

Read on, and this article will break it down for you.

Signs and Symptoms

Micronutrient deficiencies on keto

Lacking any micronutrients on keto can impose health consequences.

The signs and symptoms of micronutrient deficiencies may present themselves in rather indiscriminate manners. However, you can usually pinpoint which specific micronutrient you lack with simple blood tests.

Nevertheless, noting your symptoms may help you narrow down which micronutrient deficiency you have. You can then try eating more of that micronutrient and seeing if your symptoms subside.

Top 3 Micronutrient Deficiencies on Keto

As mentioned earlier, potassium, magnesium, and calcium tend to be the most common micronutrient deficiencies while on keto.

These three micronutrients are key electrolytes in the body, with all of them playing a role in muscle contraction, hydration, bone health, energy levels, nervous system function, and more.

Ironically enough, these minerals all interact with each other in one way or another. Thus, even if you lack just one, you’re hindering the function of all three. Think of these minerals like they comprise a tripod: if one leg breaks, the tripod falls.

Here are the major signs and symptoms to watch for if you suspect you have any of these micronutrient deficiencies on keto.

1. Magnesium deficiency

Magnesium is an essential electrolyte mineral that impacts protein synthesis, blood glucose balance, nervous system function, and blood pressure regulation.

Magnesium is necessary for energy production and contributes to the structural development of bone tissue, along with the synthesis of RNA and DNA.

Magnesium also helps potassium and calcium move across cell membranes, which is integral to muscular contraction, nerve impulse conduction, and healthy heart rhythms.

Magnesium deficiency (hypomagnesia) is becoming quite common these days. Estimates suggest as little as 10% of adults in the United States meet the recommended daily intake (RDI) of magnesium (which is around 400 mg).

Research also contends that as little as 40% of the magnesium we consume actually gets absorbed by the body.

The average adult human body contains roughly 25 grams of magnesium, with about half of that found in bones and the rest in soft tissues (and blood, to a small extent).

Common signs and symptoms of magnesium deficiency on keto:

  • Nausea and vomiting
  • Constipation
  • Feelings of anxiety
  • Muscle cramping
  • Lethargy and malaise

2. Calcium deficiency

Since the keto diet tends to have only small amounts of dairy, calcium deficiency can be quite common. However, several very-low-carb dairy foods are rich in calcium, particularly aged cheeses.

Various fish are also packed with calcium…

Calcium is another essential mineral and electrolyte involved in many biological processes. The most notable role of calcium in the human body is in maintaining bone tissue.

As we age, calcium levels in bone tissue tend to decline; if this becomes a chronic issue, bone mineral density drops and osteoporosis can manifest. As such, consuming plenty of calcium from low-carb food sources is key for those on the keto diet.

Calcium is also necessary for healthy vitamin D status and supporting the absorption of magnesium.

The tricky aspect of detecting calcium deficiency (hypocalcemia) on keto is that the symptoms don’t present themselves in the short-term. Your body maintains a balance of calcium by taking it from bone tissue whenever necessary.

Over time, however, low calcium levels can cause a variety of signs and symptoms.

Common signs and symptoms of calcium deficiency on keto:

  • Irritability
  • Muscle twitching and cramps
  • Frail bones (increased likelihood of fractures)
  • Osteoporosis and osteopenia
  • Dental issues (brittle teeth, irritated gums, etc.)

3. Potassium deficiency

Potassium is an essential mineral, playing a myriad of roles in the human body. It is especially crucial for regulating cellular hydration, muscle contraction, nerve function, insulin production, and cardiovascular health.

Potassium deficiency (hypokalemia) is generally the result of a low-potassium diet in conjunction with an excessive fluid loss.

As such, common causes of potassium deficiency include chronic diarrhea, vomiting, sweating, and lack of water intake. (Potassium deficiency is considered to be a blood potassium value below 3.5 mmol per liter.)

A recent national survey found that approximately 98% of Americans fall short of the recommended daily intake (RDI) for potassium, which is 4,700 mg.

The traditional Western diet is a likely culprit for potassium deficiency. It favors processed and nutrient-devoid foods as opposed to whole fruits, veggies, nuts, beans/lentils, etc.

Common signs and symptoms of potassium deficiency on keto:

  • Fatigue and general weakness
  • Constipation and indigestion
  • Heart palpitations
  • Muscle spasms and cramping
  • Difficulty breathing

Best Keto Food Sources for Calcium

Food Milligrams Calcium
(mg) Per 100-Gram (g)
Daily Value
Whitefish (Alaskan), cooked 810 81
Fresh Cheddar Cheese 721 72
Sardines, canned (in oil) 382 38
Salmon, Atlantic, farm-raised, cooked 277 28
Shrimp, peeled 145 14
Fresh Goat Cheese 140 14
Scallops, cooked 115 12
Watercress, raw 114 12
Egg, whole, cooked 53 6

Best Keto Food Sources for Magnesium

Food Milligrams Magnesium
(mg) Per 100-Gram (g)
Daily Value
Almonds, dry roasted 320 80
Cashews, dry roasted 290 70
Peanuts, dry roasted 260 60
Peanut Butter, smooth 149 36
Whitefish (Alaskan), cooked 85 21
Spinach, raw 79 20
Scallops, cooked 55 14
Salmon, Atlantic, farm-raised, cooked 38 10
Halibut, cooked 32 8
Chicken Breast, roasted 29 7
Avocado 29 7
Ground Beef, 90% lean, pan-broiled 27 6
Broccoli, steamed 17 4

**Note: Watch your carbohydrate intake from nut sources if you’re eating them to reach your magnesium needs on the keto diet. 

Best Keto Food Sources for Potassium

Food Milligrams Potassium
(mg) Per 100-Gram (g)
Daily Value
Whitefish (Alaskan), cooked 1080 31
Beet greens, cooked 880 26
Butterbur, raw 616 18
Clams 615 18
Spinach, raw 558 16
Avocado 507 14
Scallops, cooked 476 14
Zucchini, raw 459 13
Bok Choy, boiled 370 11
Watercress 330 9

Supplements for Micronutrient Deficiencies on Keto

First and foremost, you should not rely on any supplement for meeting your micronutrient needs on the keto diet. If you are consuming several servings of the foods listed above, it should be fairly simple to get enough calcium, magnesium, and potassium daily.

If you find that you’re still falling short of micronutrients, you may want to consider supplementing with either a multivitamin or electrolyte blend.

It’s important to note that many multivitamin supplements contain synthetic forms of vitamins and minerals that are not well-absorbed by the human body.

In turn, your body doesn’t utilize the vitamins and minerals effectively, and you won’t see much benefit.

For example, magnesium oxide is a common form of supplemental magnesium, which research suggests has less than 3% bioavailability.

This means you will need to take a whopping 1000 mg dose of magnesium oxide to reach even 10% of the daily RDI for magnesium.

Micronutrient Deficiencies on Keto: Key Takeaways

If you’re consuming the right low-carb veggies, fruits, and healthy fats, you should be getting all the necessary water-soluble and fat-soluble vitamins you need.

However, in some instances, mineral deficiencies can present a cause for concern on the keto diet, particularly magnesium, calcium, and potassium.

If you find yourself at risk for micronutrient deficiencies on keto, be sure to incorporate foods that are rich in the micronutrient you’re lacking.

You may also want to use a multivitamin or mineral supplement if necessary. Just make sure that it contains bioavailable micronutrients.