It is possible for a person to have a dietary deficiency in potassium. Although this is not relatively common, it could occur and lead to hypokalemia, that is, low levels of potassium in the person's bloodstream. It is not a particularly likely issue, unless there has also been significant loss of potassium for one reason or another.
Treatment by eating foods high in potassium
Modifying one's diet to include more potassium rich foods can be long-term remedy for hypokalemia (note: if the levels of this mineral are low enough that there is already a medical emergency, then it is not a short-term treatment in order to return the potassium levels to proper amounts).
The diet can be altered in such a way that a person can still eat foods that he enjoys while obtaining enough of this mineral for his body. In other words, if you don't like bran, you don't necessarily have to eat it just to get enough of the mineral!
Some suggestions for foods
Do you like fruit? Apricots are rich in potassium. Another possible item that is naturally sweet is the banana. If you like citrus fruit more, try eating an orange or having freshly squeezed orange juice.
For some people, vegetables might be more preferable. Spinach is high in potassium. Brussel sprouts are also a useful natural source of this mineral. Many people enjoy tomatoes and products made from them, and they can also be used in this diet.
Do you like legumes? Lima beans would then be a possibility for you to add to a potassium rich diet. Although peanuts are not usually considered legumes, they technically are, and peanut butter is a nice choice in this category.
Are you still not finding anything that you would like to add (or add more of) to your meals? Consider drinking more milk. Furthermore, this mineral is found in meats, as well as fish. There really are options for just about every range of taste buds.
If, for any reason, you don't want to eat any of the foods already mentioned, or already consume enough of them that you'd rather not add more to your daily intake, then there are still other foods that are particularly high in this mineral. Additionally, there are some that are only somewhat rich in it. As a few examples, you could try apple juice, celery, corn, mushrooms, onions, or zucchini. A dietary deficiency of potassium can be fixed through a variety of different food additions.