By: Dr. Ameya Tripathi, Asstt. Editor-ICN
LUCKNOW: Potassium, a chemical agent in periodic table with symbol “K”, atomic number 19 is an alkali metal. Right after its discovery by sir Humphry Davy in 1807, it was gradually found that potassium is an essential element in human body and conduces a plethora of important functions. Right from physiological function to neural, cardiac, muscular propagation to hormone secretions, hormone secretion and action, vascular tone, systemic blood pressure control, gastrointestinal motility, acid–base homeostasis, and various other important functions.It plays a role in bone health as it blocks certain substances in the body that promote the breakdown of bones.
Not only does it guard against the weakening of supporting structures like the jaw, but it also is essential in blood clotting. This means if your gums occasionally bleed when you floss, or if you suffer an oral injury, the blood will clot more efficiently and the wound will be able to heal more quickly. Potassium and its role are often underestimated regarding overall health and wellbeing.
The importance of potassium cannot be stressed enough. The topic is so vast that we will go through this topic in our report series.
Potassium is a mineral that’s found in the foods you eat. It’s also an electrolyte. Electrolytes conduct electrical impulses throughout the body. They assist in a range of essential body functions, including:
blood pressure
normal water balance
muscle contractions
nerve impulses
digestion
heart rhythm
pH balance (acidity and alkalinity)
Potassium isn’t produced naturally by the body, so it’s important to consume the right balance of potassium-rich foods and beverages.
Potassium, the most abundant intracellular cation, is an essential nutrient that is naturally present in many foods and available as a dietary supplement. Potassium is present in all body tissues and is required for normal cell function because of its role in maintaining intracellular fluid volume and transmembrane electrochemical gradients. Potassium also regulates plasma volume as with sodium it regulates volume of extracellular fluid.
There is a sodium-potassium gradient, in addition to maintaining cellular tonicity, this gradient is required for proper nerve transmission, muscle contraction, and kidney function. Potassium is absorbed via passive diffusion, primarily in the small intestine. About 90% of ingested potassium is absorbed and used to maintain its normal intracellular and extracellular concentrations. Potassium is excreted primarily in the urine, some is excreted in the stool, and a very small amount is lost in sweat.
The kidneys control potassium excretion in response to changes in dietary intakes, and potassium excretion increases rapidly in healthy people after potassium consumption, unless body stores are depleted. The kidneys can adapt to variable potassium intakes in healthy individuals, but a minimum of 5 mmol (about 195 mg) potassium is excreted daily in urine. This, combined with other obligatory losses, suggests that potassium balance cannot be achieved with intakes less than about 400–800 mg/day.
Recommended Intakes
Intake recommendations for potassium and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by an expert committee of the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and sex, include:
Recommended Dietary Allowance (RDA): Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals.
Adequate Intake (AI): Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA. The AIs for potassium are: 400 mg of potassium for 0-6-month-old males, 700 mg of potassium for 7-12-month-old males, 3,000 mg of potassium for 1-3-year-old males, 3,800 mg of potassium for 4-8-year-old males, 4,500 mg of potassium for 9-13-year-old males, and 4,700 mg of potassium for males that are 14 years old and older. The AIs for potassium are: 400 mg of potassium for 0-6-month-old females, 700 mg of potassium for 7-12-month-old females, 3,000 mg of potassium for 1-3-year-old females, 3,800 mg of potassium for 4-8-year-old females, 4,500 mg of potassium for 9-13-year-old females, and 4,700 mg of potassium for females that are 14 years old and older. The AIs for potassium are: 4,700 mg of potassium for 14-50-year-old pregnant females; furthermore, 5,100 mg of potassium for 14-50-year-old lactating females.
Estimated Average Requirement (EAR): Average daily level of intake estimated to meet the requirements of 50% of healthy individuals; usually used to assess the nutrient intakes of groups of people and to plan nutritionally adequate diets for them; can also be used to assess the nutrient intakes of individuals.
Tolerable Upper Intake Level (UL): Maximum daily intake unlikely to cause adverse health effects.
Sources of Potassium
Food
Potassium is found in a wide variety of plant and animal foods and in beverages. Many fruits and vegetables are excellent sources, as are some legumes (e.g., soybeans) and potatoes. Meats, poultry, fish, milk, yogurt, and nuts also contain potassium. Among starchy foods, whole-wheat flour and brown rice are much higher in potassium than their refined counterparts, white wheat flour and white rice.
Milk, coffee, tea, other nonalcoholic beverages, and potatoes are the top sources of potassium in the diet. Among children milk, fruit juice, potatoes, and fruit are the top sources
Selected Food Sources of Potassium
Food Milligrams(mg) per serving Percent DV*
Apricots, dried, ½ cup 1,101 31
Lentils, cooked, 1 cup 731 21
Prunes, dried, ½ cup 699 20
Squash, acorn, mashed, 1 cup 644 18
Raisins, ½ cup 618 18
Potato, baked, flesh only, 1 medium 610 17
Kidney beans, canned, 1 cup 607 17
Orange juice, 1 cup 496 14
Soybeans, mature seeds, boiled, ½ cup 443 13
Banana, 1 medium 422 12
Milk, 1%, 1 cup 366 10
Spinach, raw, 2 cups 334 10
Chicken breast, boneless, grilled, 3 ounces 332 9
Yogurt, fruit variety, nonfat, 6 ounces 330 9
Salmon, Atlantic, farmed, cooked, 3 ounces 326 9
Beef, top sirloin, grilled, 3 ounces 315 9
Molasses, 1 tablespoon 308 9
Tomato, raw, 1 medium 292 8
Soymilk, 1 cup 287 8
Yogurt, Greek, plain, nonfat, 6 ounces 240 7
Broccoli, cooked, chopped, ½ cup 229 7
Cantaloupe, cubed, ½ cup 214 6
Turkey breast, roasted, 3 ounces 212 6
Asparagus, cooked, ½ cup 202 6
Apple, with skin, 1 medium 195 6
Cashew nuts, 1 ounce 187 5
Rice, brown, medium-grain, cooked, 1 cup 154 4
Tuna, light, canned in water, drained, 3 ounces 153 4
Coffee, brewed, 1 cup 116 3
Lettuce, iceberg, shredded, 1 cup 102 3
Peanut butter, 1 tablespoon 90 3
Tea, black, brewed, 1 cup 88 3
Flaxseed, whole, 1 tablespoon 84 2
Bread, whole-wheat, 1 slice 81 2
Egg, 1 large 69 2
Rice, white, medium-grain, cooked, 1 cup 54 2
Bread, white, 1 slice 37 1
Cheese, mozzarella, part skim, 1½ ounces 36 1
Dietary supplements
In dietary supplements, potassium is often present as potassium chloride, but many other forms—including potassium citrate, phosphate, aspartate, bicarbonate, and gluconate—are also used .The Supplement Facts panel on a dietary supplement label declares the amount of elemental potassium in the product, not the weight of the entire potassium-containing compound. Some dietary supplements contain potassium iodide in microgram amounts, but this ingredient serves as a form of the mineral iodine, not potassium. Not all multivitamin/mineral supplements contain potassium, but those that do typically provide about 80 mg potassium
Salt substitutes
Many salt substitutes contain potassium chloride as a replacement for some or all of the sodium chloride in salt. The potassium content of these products varies widely, from about 440 mg to 2,800 mg potassium per teaspoon. Some people, such as those with kidney disease or who are taking certain medications, should consult their healthcare provider before taking salt substitutes because of the risk of hyperkalemia posed by the high levels of potassium in these products.
The above mentioned table is just an indication to choose from variety of food options. The consumption of potassium should be optimum i.e. neither too much and nor too little. Excess potassium has its own side effects and deficiency can lead to plethora of disorder in the body. We will be discussing this in our next part of this series. Please stay tuned and share this with your near and dear ones.
