mineral
Potassium Supplements: Why 99 mg, Safety and Foods
Also known as potassium chloride, potassium citrate, potassium gluconate, potassium bicarbonate, potassium aspartate, electrolytes
Short answer
Potassium is a mineral every cell uses for fluid balance and the electrical gradients nerves and muscles need [1]. Most US supplements contain 99 mg or less, about 2% of the 4,700 mg Daily Value, because of FDA rules on higher-dose potassium drugs [1][2]. With kidney disease or some blood pressure medicines, ask a doctor first [1].
Last reviewed · 3 sources
What is Potassium?
Potassium is an essential mineral present in all body tissues [1]. The body uses it to keep fluid volume inside cells and to maintain the electrochemical gradient across cell membranes, which nerve signals, muscle contraction and kidney function depend on [1]. The kidneys control how much potassium the body keeps or excretes [1].
Forms of Potassium you'll see on labels
Potassium chloride
The most common form in supplements and the form used in salt substitutes [1].
Potassium citrate, phosphate, aspartate, bicarbonate or gluconate
Other forms used in supplements [1]. One trial found people absorb about 94% of potassium gluconate, similar to potassium from potatoes [1].
Potassium iodide
Appears in microgram amounts as a source of iodine, not potassium [1].
Salt substitutes
Often potassium chloride, with about 440 to 2,800 mg potassium per teaspoon [1].
How much Potassium do adults need?
NIH lists these Adequate Intakes (AI) for adults 19+ in mg. They do not apply to people whose kidneys or medicines limit potassium excretion. Reference values, not a personal recommendation.
| Group | Amount per day |
|---|---|
| Men 19+ | 3,400 mg |
| Women 19+ | 2,600 mg |
| Pregnancy (19–50) | 2,900 mg |
| Breastfeeding (19–50) | 2,800 mg |
Upper limit: No upper limit has been set; the expert committee found too little evidence to set one for healthy people [1]
How Potassium appears on a label
The Supplement Facts panel lists elemental potassium in mg, not the weight of the whole compound such as potassium chloride [1]. The Daily Value is 4,700 mg [1]. Multivitamins that contain potassium usually have about 80 mg, and most potassium-only supplements contain up to 99 mg [1]. Many makers stop at 99 mg because FDA requires some potassium drug products above that level to carry warnings about small-bowel lesions [1][2]. Medical sources may use mEq: 1 mEq = 1 mmol = 39.1 mg potassium [1].
When to take Potassium
No source we checked names a best time of day or says whether to take low-dose potassium supplements with food. For some prescription potassium products, FDA-required labeling tells prescribers to have patients dissolve tablets or dilute liquids in enough liquid to protect the gut [2]; follow your prescriber's directions.
What to keep apart from Potassium
ACE inhibitors and angiotensin receptor blockers (ARBs)
These blood pressure medicines reduce potassium excretion and can lead to high potassium (hyperkalemia) [1]. Ask your pharmacist before adding potassium.
Potassium-sparing diuretics
Medicines such as amiloride and spironolactone can cause hyperkalemia [1]. Ask your pharmacist.
Loop and thiazide diuretics
These increase potassium loss in urine and can lead to low potassium; NIH says experts recommend monitoring [1]. Ask your doctor.
Salt substitutes
Many contain a lot of potassium. People with kidney disease or on certain medicines should check with a provider first [1].
Magnesium
Low magnesium can increase potassium loss in urine; when both are low, they are treated together [1].
Laxatives and enemas
Large doses or repeated use can cause low potassium through losses in stool [1].
Foods that contain Potassium
- Dried apricots, prunes and raisins
- Lentils, kidney beans and soybeans
- Acorn squash
- Potatoes
- Orange juice
- Bananas
- Milk and yogurt
- Spinach and broccoli
- Chicken, salmon and beef
- Nuts and seeds
Who should ask a doctor or pharmacist first
Talk to a doctor or pharmacist before taking potassium supplements or salt substitutes if you have chronic kidney disease, or take ACE inhibitors, ARBs or potassium-sparing diuretics, since even normal intakes can cause hyperkalemia in these cases [1]. Hyperkalemia can also occur with type 1 diabetes, heart failure, adrenal insufficiency or liver disease [1]. The NHS says older people should not take potassium supplements unless a doctor advises it [3].
Keep Potassium in a routine that fits
Supin schedules what you take by time of day, reminds you, and tells you when a bottle runs low.
Potassium: questions people ask
It depends on the medicine. ACE inhibitors, ARBs and potassium-sparing diuretics can raise potassium, while loop and thiazide diuretics lower it [1]. Ask your doctor or pharmacist.
High potassium can cause no symptoms, but severe cases can cause muscle weakness, paralysis, palpitations, tingling and dangerous heart rhythms [1].
Yes. Many replace sodium chloride with potassium chloride and provide about 440 to 2,800 mg potassium per teaspoon [1].
Dried apricots, lentils, acorn squash, prunes, raisins, potatoes, kidney beans and orange juice are among the top foods in NIH's list [1].
Sources
- Potassium - Health Professional Fact Sheet — NIH Office of Dietary Supplements
- 21 CFR 201.306 – Potassium salt preparations intended for oral ingestion by man — U.S. Food and Drug Administration (Electronic Code of Federal Regulations)
- Vitamins and minerals: Others — NHS
Educational information, not medical advice. The amounts above are official reference values, not a recommendation for you. Check with your doctor or pharmacist before starting or changing supplements, especially if you take medication, are pregnant or have a health condition. Supin sells a subscription, not supplements. Last reviewed .