One of the problems with many forms of weight loss surgery, and in particular absorptive forms of surgery such as the Roux-en-Y and vertical sleeve gastrectomy with duodenal switch, is that gastric bypass surgery not only reduces the number of calories which the body can absorb from the food eaten, but also prevents the take-up of the necessary level of vitamins and minerals. For this reason, anybody undergoing bariatric surgery must take vitamin and mineral supplements for the remainder of their life.

Just how important this is was demonstrated by the recent publication of a study showing that a number of patients who had failed to take the supplements prescribed following surgery developed a condition known as Wernicke encephalopathy. This is a serious, though entirely preventable, brain illness brought on by a deficiency of thiamine, a B complex vitamin.

For weight loss surgery patients who fail to take post-operative supplements, and in particular for women under the age of 55, the illness normally appears within one to three months of surgery, although it can appear many months post-operatively, and is characterized by vomiting, a lack of coordination, confusion and involuntary eye movements, which can lead to limited vision. If untreated, the condition can prove fatal.

In the majority of cases the problem can be reversed by the administration of B1, although the illness can often only be cured completely if it is caught in its early stages and, if left, patients may suffer ongoing difficulties for many years.

It should be stressed that Wernicke encephalopathy is not a common condition and that only a very small percentage of the many thousands of people who are currently undergoing gastric bypass surgery each year are likely to suffer from it. It is nonetheless only one of the many complications which can arise after weight loss surgery and, having put yourself through the trauma of surgery, it would seem silly to succumb to complications simply because you couldn't be bothered to take your daily vitamin and mineral supplements.

One final point. One relatively common side effect of gastric bypass surgery is vomiting which means that, even when you do take your vitamin and mineral supplements, they may not be doing their job if they are being vomited straight up again. In these circumstances it is possible to develop Wernicke encephalopathy in spite of taking your supplements. Accordingly, if you find yourself vomiting and this is accompanied by other symptoms such as a lack of coordination, confusion and visual difficulties then you should seek medical advice without delay.