I have a feeling the low potassium myth comes from not eating your bananas and potatoes, which Everyone Knows(tm) are necessary for human health. Plenty of LC foods are quite high in potassium: avocados, fish, meat, other veggies.

Re supplements: the pills are only 99mg. In contrast, a pork chop has about 500 mg, salmon about 700 mg, and an avocado has over 1000 mg.

If you think you're short on potassium but not sure, a good bet is the NuSalt (Potassium salt instead of sodium.) You can put in on your food in modest amounts but it would be pretty hard to overdo it.