Heart failure and arrhythmia are major health conditions that affect millions of people worldwide. While medical sciences, different devices and medications have improved prognosis in last few years, researchers continue to explore new and simple ways to support heart health, function and reduce the risk of complications. One of such nutrients that has been receiving growing attention is: Potassium.



Potassium is best known for its role in regulating blood pressure and balance fluid , both of which are vital for keeping electrical activity within the heart proper. But, having too little or too much potassium can be hazardous, which is why apt amount of potassium should be closely regulated. In the past few years, scientists started wondering if slight levels of potassium, within a normal range could be safe for patients with heart risks, and the results....



The POTCAST trial : Targeting high-normal potassium






Vitamin K, potassium, was tested on a large group of people and its results were published in
The New England Journal of Medicine in 2025. The trial was called
POTCAST trial and it examined if boosting potassium intake in the blood slightly could prevent dangerous heart rhythm problems in individuals who are at high risk.



The trial involved over 1,200 patients with implantable cardioverter-defibrillators (ICDs) or combination devices that regulate heartbeats. Each of them had potassium levels at or below 4.3 mmol/L, which is normal but at the lower limit. Participants were randomly assigned to either maintain standard care or to take action to increase their potassium level to the higher limit of normal, 4.5 to 5.0 mmol/L.



To properly carry out the research, the team of researchers utilised a mixture of dietary recommendations and potassium supplements. After a follow up for three years, the group with increase in potassium in their blood experienced a significant decrease in the occurrence of serious events and life threatening arrhythmias, heart failure, device interventions etc.



Overall, the risk decreased by approximately 24 percent compare to the usual care group.

Notably, the trial also revealed that this approach was safer than all. Dangerous high or low potassium levels in the body were extremely rare and hospitalization due to potassium imbalance occurred in few cases in each group.



Why do these results matter




These results indicate that the target of a higher-normal level of potassium may be an easy, inexpensive approach to lowering the risk of serious heart complications in patients who are already at the risk for heart abnormalities.



While additional studies are necessary to determine if the same strategy helps individuals without devices or with other forms of heart failure, this research paves the way to novel strategies with something as simple as potassium to enhance results.



At last, diet or any kind of supplements need to be taken under the advice of trained medical practitioner, specifically those who suffer from kidney issues and are on specific medications. This study might present a new hope for a significant impact on cardiovascular well-being.



How to increase potassium intake (dietary sources)

• Fruits: Bananas, oranges, cantaloupe


• Vegetables: Sweet potatoes, spinach, beets, carrot


• Dairy: Milk, yogurt

How much potassium should one take (according to NIH)


Female (19-50 years)- 2600mg, if lactating, 2500mg

Male (19-50 years)- 3400mg (
NIH)