Is a 99 mg potassium supplement safe?

99 milligrams of potassium has no set upper limit. Adults need an adequate intake of 3,400 milligrams for men and 2,600 milligrams for women.

Checked 28 September 2026 · Sources: NIH Office of Dietary Supplements fact sheet and NHS vitamins and minerals guidance · Adults onlyUS: No upper limit setUK: Within NHS guidance

General information, not medical advice. Check with a doctor or pharmacist before taking a supplement, especially if you are pregnant or breastfeeding, take any medicine, or are under 18.

In the UK

99 milligrams of potassium is within the NHS guidance of 3,700 milligrams a day from supplements. In the UK, adults need 3,500 milligrams a day.

The figures

US (NIH)UK (NHS)
Amount checked99 mg
AnswerNo upper limit setWithin NHS guidance
Compared withNo upper limit has been set for potassium in healthy people.3,700 milligrams a day from supplements
Share of the limitNo limit to compare3% of the limit
Adults needAn adequate intake of 3,400 milligrams for men and 2,600 milligrams for women3,500 milligrams a day

Good to know

Quick answers

Is a 99 mg potassium supplement safe?
99 milligrams of potassium has no set upper limit. Adults need an adequate intake of 3,400 milligrams for men and 2,600 milligrams for women.
What does the NHS say about 99 mg of potassium?
99 milligrams of potassium is within the NHS guidance of 3,700 milligrams a day from supplements. In the UK, adults need 3,500 milligrams a day.
What is the upper limit for potassium?
US: No upper limit has been set for potassium in healthy people. UK (NHS): 3,700 milligrams a day from supplements.

Sources

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