About 3 weeks ago I had an extremely bad case of food poisoning, with a LOT of vomiting, diarrhea and dehydration over the course of two days. Since then, I've been taking vitamins and trying to eat things like kale every day, but about a week after the poisoning I began getting leg pains behind both knees, and a general feeling of weakness when bending the knees or putting weight on them. It's progressed to be more in my right leg, and for a while some days were almost okay and some were worse, but today I'm at the point where I can barely walk. A side factor may be an alcohol problem, but I think this is not necessarily related, as this came on fairly fast and doesn't seem to be the same as alcohol-related leg issues. I'm female and 50 years old, and also about 100 pounds overweight, but I also have lost 50 pounds in the last year and do a lot of walking and drink a lot of water, and am in fairly good shape (normally). Could this be a vitamin deficiency brought on by the food poisoning, or...?