Why We Need Potassium (K)?

By Dr Harold Gunatillake
Health writer
FRCS, FACS (US), FIACS (US),
AM (SING), MBBS (Cey)

We are concerned about cholesterol, saturated fats and many other health foods influenced by consumer pressure, and ignore discussions on more essential nutrients and other foods. Basically all good foods that you consume would be a source of potassium, and contains on an average 200 milligrams of potassium.
The Food and Nutrition Board of the National Academy of Sciences has estimated the minimum requirements for potassium for men and women over 18 years of age to be 2,000 milligrams per day.
Most of your potassium comes from fruits and vegetables. While potatoes, though given a bad name, provides about one third of the potassium. Meat, poultry, and fish provide about 20 per cent of the potassium.
Potassium is an essential mineral, an electrolyte and assists in muscle contractions and in maintaining body fluid and electrolyte balance in all body cells. It is needed to keep our body’s pH in balance.
It is essential for the normal electrical activity of the heart. It is necessary for the building of muscle and for normal body growth. It assists in protein synthesis from amino acids and in carbohydrate metabolism.
Lack of potassium can cause a severe imbalance, and can cause muscle cramps, weakness, tiredness, and affect the workings of the heart muscles, too. Potassium assists the nerves in sending nerve impulses as well as releasing energy from protein, fat and carbohydrates during normal metabolism. Sodium and potassium work together to regulate our water balance in the cells of the body. For potassium to be beneficial in the body the proper amount of sodium needs to be in balance.
By taking more sodium in our food may cause elevation of blood pressure. This is one reason that one should limit eating processed food containing large amounts of sodium needed for processing. Potassium is found in 95% of the fluid in the cells, which is significant.
Some patients who suffer with hypertension benefit from using potassium daily because of its blood pressure lowering abilities.
It has been shown that taking potassium may be able to help prevent kidney stones from developing in the kidney. Kidney stones are formulated by calcium being in the kidneys, the potassium acts as an agent to keep the calcium from forming stones. The kidneys filter potassium and eliminate it in our urine. Drinking alcohol in excess and coffee tends to deplete potassium through urination, and you tend to retain sodium.
Eating mostly restaurant and convenience foods and not eating enough fruits and vegetables may cause potassium deficiency and excess of sodium retention in the body fluid.
Boiling tends to lose potassium. For example, a boiled potato has almost half the potassium of a baked potato. To preserve potassium, eat fruits and vegetables raw, or roast or lightly steam them.
When dining out, increase potassium by ordering a salad, extra steamed or roasted vegetables, bean-based dishes, fruit cups, and low-fat milk instead of soda.
Lack of potassium may cause the following symptoms:
•       Irritability
•       A fast heartbeat
•       Excessive sweating
•       Fatigue
•       Muscle weakness
•       Irregular heartbeats – The heart is composed of smooth muscles contracting and relaxing right through life. Potassium is very important to heart health, and is dependent on it for electrical transmission. When potassium is out of balance in the heart, then the actual heart beat is affected. Large changes are enough to stop it altogether; it is a matter of record that heart attacks are associated with low blood potassium and low potassium intake. It is possible that the lack of potassium in the coronary muscles is a major factor in death from heart disease.
•      Bowel irritability – Potassium regulates the movements of the involuntary smooth muscles of the bowel. Babies losing water and potassium deficiency can be saved by administering of potassium. Potassium seems to control excess fungi and bacteria in the intestines.
•       Blood sugar levels – Potassium is essential for the correct functioning of the pancreas.
When people with low blood sugar (hypoglycaemia), have been given 2-5 grams of potassium chloride daily, blood sugar has increased quickly and all symptoms have disappeared.
Serum Potassium levels impaired with diarrhoea,
uncontrolled vomiting,
dehydration and an orexia (lack of appetite).
Remember to eat potassium rich foods most of the time.
They are: Sweet potato, medium, baked with skin: 694 mg Potato, medium, baked with skin: 610 mg
White beans, canned, drained, half cup: 595 mg
Yogurt, fat-free, 1 cup: 579 mg
Halibut, 3 ounces, cooked: 490 mg
100% orange juice, 8 ounces: 496 mg
Broccoli, 1 cup, cooked: 457 mg
Cantaloupe, cubed, 1 cup: 431 mg
Banana, 1 medium: 422 mg
Pork tenderloin, 3 ounces, cooked: 382 mg
Lentils, half cup, cooked: 366 mg
Milk, 1% low fat, 8 ounces: 366 mg
Salmon, farmed Atlantic, 3 ounces, cooked: 326 mg
Pistachios, shelled, 1 ounce, dry roasted: 295 mg
Raisins, quarter cup: 250 mg
Spinach is very high in potassium content.
Tomato, tomato juice and sauces contain high potassium.
Pineapples contain high potassium levels.
Cow’s milk 143 mg per 100mls
Yoghurt is an excellent source of potassium.

Spices

All spices contain high levels of potassium. Good examples are saffron, fennel seeds, peppers, cumin seeds, and curry powder, among others.

Coconut water

Young tender coconut water has sufficient potassium to quench your thirst. It is delicious, refreshing and very nutritious and has tremendous health benefits. The water of tender young coconut technically is the liquid endosperm.
It is one of the purest, most nutritious wholesome waters and beverages with which nature has provided us.
The people in tropical regions and countries have been enjoying this drink for centuries. They have used the all-natural coconut water to  refresh, refuel, re-hydrate, feed and maintain the proper
nourishment and fluid levels in their bodies.  The natural water has a caloric value of 17.4 per 100 gm.
The benefits of coconut water are endless and should be an essential and integral part of a healthy diet.
Eleven Fluid ounces of coconut water contains 530g of potassium, and 85mg o sodium, and contains 65 calories, and no fat content.

Problems with too much or too little potassium

Hypokalaemia

This is a term used due to low levels of potassium in blood due to metabolic disorders.
A deficiency of potassium (hypokalaemia) can happen in people with certain diseases or as a result of taking diuretics (water pills) for the treatment of high blood pressure or heart failure.
Additionally, many medications – such as diuretics, laxatives, and steroids – can cause a loss of potassium, which occasionally may be very severe.
You should have your blood levels of potassium checked from time to time if you take any of these medicines. Diuretics are probably the most common cause of hypokalaemia.

Hyperkalaemia

This is a state where the blood potassium level is higher than required. Kidneys normally remove the excess potassium in urine. Kidney disorders tend to retain potassium and cause many problems.
The hormone aldosterone regulates kidney removal of sodium and potassium.  Lack of aldosterone can result in hyperkalaemia with an increase in total body potassium.
Addison’s disease is one disorder that causes reduced aldosterone production.
When potassium is released from the cells, it tends to accumulate in the body fluids outside the cells. If kidneys are not functioning the potassium level in the fluids rises and alters the pH of the body.
Tissue injury can also cause the cells to release potassium and increase in the extra-cellular fluids.
Patients having kidney failure may need to restrict potassium containing vegetables and foods, until renal dialysis is indicated.
Accordingly, the Foundation recommends that kidney patients whose serum potassium is more than 5.0 mg/dl consume no more than one cup of milk or a 1/2 cup of yogurt a day.
Since cheese is also made from milk, it is reasonable to suspect that cheese is a high potassium food as well.
However, since different cheeses have different levels of potassium, the answer is a little more complex. High-potassium cheeses are those that have more than 200 mg in a single serving.  Generally, cheeses with large serving sizes are higher in potassium. For example, with 217 mg of potassium, 1 cup of low-fat cottage cheese is considered a high-potassium food.  Likewise, 2/3 of a cup of ricotta cheese is considered a high-potassium food because it has 205 mg of potassium.  Cheeses that are customarily eaten in small servings are considered low-potassium foods.  For example, with only 28 mg of potassium, 1 oz. of cheddar is a low-potassium food.  Likewise, blue cheese has 73 mg of potassium per ounce, and 1 tbsp. of low-fat cream cheese has only 28 mg.  However, portion control is important because eating too much of these cheeses can introduce too much potassium for people who need to restrict total potassium.

Potassium in Grains

Potassium is a vital mineral found in many foods including grains. Grains are complex carbohydrates that provide an array of essential vitamins and minerals. While not a rich source of potassium, you can combine with other potassium-rich foods to meet your daily recommended intake.
The grains that provide the highest amount of potassium include whole grains.
Examples include wheat germ, wheat bran, buckwheat, barley, brown rice, oats, and durum wheat.
A half cup of rye flour provides 459 mg of potassium, while a half cup of crude wheat bran provides 343 mg, and a half cup of wild rice provides 342 mg.
Grains that include the bran are typically higher in potassium than refined or white grains. These include rice bran, wheat bran and corn bran.
White rice and white bread provide significantly lower levels of potassium.
A half cup of short-grain white rice provides only 24 mg of potassium.
Adults require 4,700 mg of potassium every day. Breastfeeding or pregnant women require more – approximately 5,100 mg of potassium daily.  Children require only 3,000 to 3,800 mg of potassium every day. Athletes may require greater amounts of potassium daily. The bottom line is that check your electrolytes regularly, and also when you don’t feel well.