A recent study shows a linkage between deficiencies in Vitamin D and increased rheumatoid arthritis. The study group was small - only 97 patients.

Overall the study found that: severely deficient patients had slightly longer (rheumatoid arthritis) disease duration (8.8 years versus 5.8 years), more hypertension (60.9 percent versus 49 percent), and osteoporosis (20.3 percent versus 8.7 percent).

So for bariatric patients, get the exercise (and exposure to sunshine) and take the Vitamin D supplements to minimize rheumatoid arthritis, hypertension and osteoporosis.

http://www.everydayhealth.com/news/link-between-vitamin-d-deficiency-ra/?ncid=txtlnkusaolp00000058

As soon as I began contemplating surgery my surgeon's office has required that I take a D3 supplement daily.