From Science Daily:
Low levels of vitamin D have long been identified as an unwanted hallmark of weight loss surgery, but now findings of a new Johns Hopkins study of more than 930,000 patient records add to evidence that seasonal sun exposure — a key factor in the body’s natural ability to make the “sunshine vitamin” — plays a substantial role in how well people do after such operations.
Results of the study, published online Dec. 14 in the journal Obesity Science & Practice, reveal interplay among vitamin D status, seasons, geography and surgery outcomes, according to Leigh Peterson, Ph.D., M.H.S., a nutritionist and postdoctoral research fellow at the Johns Hopkins Center for Bariatric Surgery, who led the research.
Specifically, the researchers found that patients undergoing bariatric surgery in the United States during winter — January to March, the time of lowest vitamin D levels — fared worse than patients who had procedures in the summer. Similarly, patients having surgery in the north seemed to have more complications than those in the south.
“Sun exposure is critical in the synthesis of vitamin D, so the notion that people living in less sunny northern states may suffer from vitamin D deficiency is not surprising,” says Peterson. “What is remarkable is how closely sun exposure, vitamin D and surgical outcomes were linked.”
For the study, researchers reviewed records of more than 930,000 bariatric operations performed in the United States between 2001 and 2010. Overall, they report, post-procedural complications were rare, with fewer than 1 percent…