09/01/2016 01:46 pm ET Updated Sep 02, 2017

Too Little Potassium May Lead To Big Problems

My friend, who is undergoing chemotherapy, was admitted to the hospital because of an infection but blood tests revealed another very serious problem. Her potassium levels were extremely low and, despite getting potassium intravenously, the unfortunate effects became apparent very quickly. Her heart began beating abnormally, her blood pressure shot up, and even though she was given a drug to prevent blood clots, one found its way to her brain. Consequently, she suffered a stroke. The infection was soon gone, but the effects of her low potassium remained many days later.

Potassium is one of those minerals that we usually don't think about. If one eats a healthy diet with lots of vegetables and fruit, then potassium levels are usually within the range of what the body needs, about 4700 mg a day. But surveys of potassium intake in the U.S. population indicate that as whole, we don't get enough of this mineral. Indeed, the average intake is 2640 mg a day, and that level has remained unchanged for decades.

"So what?" might be one's response to this data. "I feel fine!"

Perhaps we should not be so complacent about whether we are getting enough of this mineral. Most of us, I hope, will not have to endure the toll of chemotherapy on the body and experience the side effects that can reduce potassium levels. My friend had mouth sores that prevented her from eating for days, along with gastrointestinal side effects, thus causing a significant loss of potassium from her body.

But also consider these other factors:

• A gastro-intestinal infection that causes prolonged dehydration may reduce potassium levels so much that it is necessary to get medical attention and potassium supplementation;

• Going on a high protein, low or carbohydrate-free diet can also drastically lower potassium levels because, as the body loses water due to diminished stores of carbohydrate, the body is also losing potassium. And it is almost impossible for such a diet to restore potassium because foods rich in this mineral -- i.e. potatoes and bananas -- contain carbohydrate and cannot be eaten. The effects of potassium loss on these so-called ketogenic diets is known as keto-flu. Followers of such diets feel 'wasted' and totally exhausted with flu-like symptoms. Since potassium is needed for normal muscle function including the heart (a muscle) experiencing such fatigue should be a sign to balance eating critically important nutrients with weight loss on an extreme diet;

• Prolonged fasting or cleanses and extremely limited food intake after bariatric surgery may also lead to low potassium. Post-surgery, bariatric patients are usually given potassium supplements;

• Alcoholics may have dangerously low potassium levels;

• Athletes engaging in prolonged strenuous exercise associated with excessive sweating also lose significant amounts of potassium;

• Medicines such as diuretics cause potassium loss (as does laxative abuse);

If potassium levels are marginally low to begin with, a further decrease may, as with my friend, generate potentially dangerous side effects. (Hypokalaemia, the term for low potassium, is defined as potassium blood levels below 3.5 mmol/L. If potassium is among the items measured when you have a blood test, the computer will list the potassium level as mmol/L and note if your level is below normal. ) However, an adequate potassium intake and blood levels are important for all of us, even if we are not strenuous athletes, recovering from bariatric surgery, following a carbohydrate-free diet or receiving chemotherapy. Too little potassium may lead to elevated blood pressure, kidney stones, and/or bone loss. Conversely, obtaining enough potassium in the diet may reduce the risk and severity of these conditions.

Consuming enough potassium is not hard, or at least should not be hard, if one is willing to eat vegetables and fruit every day. Bananas are high in potassium (everyone seems to know this). But for banana haters, there are many more options, some with considerably more potassium than bananas.

Here are a few high potassium foods: sweet and white potatoes, white beans, plain yogurt, milk, halibut, cod and tuna, winter squash, spinach, peaches, papaya, raisins, prunes, oranges, soybeans, tomatoes, melon, beef, peanut butter, and turkey (dark meat). There are many more foods with moderate potassium contents, mostly vegetables like mushrooms, Brussels sprouts, cooked zucchini, avocado, carrots, asparagus, and broccoli.

Let's face it. Conversations about potassium are boring. People might boast about their good and bad cholesterol levels but I, for one, have never heard anyone boast about his or her potassium levels. In fact, potassium is usually only mentioned when someone needs to take a supplement and complains about the size of the pill, which is enormous. But, as the saga of my friend's many medical problems indicate, we cannot be blasé and disinterested in our potassium levels. The potential health risks are too high. Eating enough of the foods on the list (and the list was not at all comprehensive) to meet the daily requirement should be given a high priority when planning meals or choosing what to eat at a restaurant.

When your mother told you to eat your vegetables, she was right.