Falmina asked
I've been treated for multiple myeloma for 10 years. In last lab test, my Potassium dropped from 4.1 MEq to 3.1. Oncologist Rx'd potassium chloride capsules, 600 mg (8 MEq). I have been drinking 11.5 oz low sodium V-8 every day for years. Amount of potassium for 1 can is 1180 mg. Are the two types of potassium different, and if they are not, why can't I continue to get my potassium need from V-8 (say, 2 cans a day) instead of having to take Rx? Many thanks for your help.
Answer
Potassium is the primary cation within our cells and it plays a major role in how they function. Our body regulates potassium concentrations to achieve a certain level both inside and outside the cell but, for variety of reasons, that concentration can either go too high (hyperkalemia) or too low (hypokalemia).
Potassium is a normal component of a regular, well rounded diet and is contained in many foods such as meats, fruits and vegetables. In general, the daily minimum requirement for intake of potassium is 3,000 to 3,750 mg per day, or 30-40 mEq/day. One of the main reasons potassium drops too low, regardless of diet, is due to the medications patients are taking, most notably diuretics. Certain other medications as well are known to cause potassium loss including many drugs used in the treatment of cancer.
A common question is whether or not we can just increase our dietary intake of potassium, rather than take a potassium supplement medication such as potassium chloride. While increasing dietary intake of potassium may certainly work for some people, there are reasons why your doctor might prescribe potassium in addition.
First and foremost, as we mentioned above, medication therapy is one of the most common causes of low potassium. In addition to the potassium loss created by these medications, chloride is often also lost from the body in significant amounts. Supplementing with potassium chloride medications helps to replenish BOTH potassium and chloride, which can be difficult solely via dietary means in some people as dietary potassium typically comes as a phosphate salt, not the chloride salt. There are a variety of other potassium salt medications available as well, such as potassium citrate and potassium gluconate, that are prescribed for different reasons, most notably to balance out our body acid-base levels.
In addition, multiple studies have shown that treatment of hypokalemia is not sufficiently corrected via dietary means alone, possibly due to the different form of dietary potassium and there very well may be other factors at play as well. An important distinction however, is that studies do show that increasing your dietary intake of potassium is effective in preventing hypokalemia. So once you are back in your normal range, it may be worth discussing with your doctor if a possible option is to stop supplementation and see if your dietary intake of the V-8 is sufficient to prevent low potassium from occurring again.
It is important to discuss your options with your doctor as there are a variety of factors that need to be taken into consideration in regards to regaining normal potassium levels. Dietary potassium intake of 4.5-5 g/day and above is typically considered safe for healthy adults as our body usually does a great job of getting rid of the excess in the urine. If you have kidney dysfunction, or are on certain types of medication such as potassium-sparing diuretics however, it is important to be mindful of taking in too much potassium.
