Most of the bariatric literature on thiamine deficiency surrounds gastric bypass, but it seems sleeve gastrectomy is not immune to this problem despite that, theoretically, sleeve gastrectomy experiences fewer malabsorption issues.

https://www.soard.org/article/S1550-7289(18)30222-3/fulltext

Nutritional deficiencies are a recognized complication of bariatric surgery. Thiamine deficiency has been reported as a possible consequence of both restrictive and malabsorptive bariatric procedures. Most of the reported cases occurred after Roux-en-Y gastric bypass (RYGB) surgery; fewer were described after biliopancreatic diversion, vertical banded gastroplasty, or duodenal switch. Adults who have a high carbohydrate intake derived mainly from refined sugars and milled rice are at greater risk of developing thiamine deficiency because thiamine is absent from fats, oils, and refined sugars.

https://www.soard.org/article/S1550-7289(05)00726-4/fulltext

Thiamine was the first vitamin B to be discovered. It is absorbed in the proximal jejunum and is mainly stored in muscle as thiamine pyrophosphate. It has a biological half-life of 9-18 days. Patients who experience persistent vomiting after bariatric surgery are at risk of developing thiamine deficiency. Mild deficiency should be suspected if patients complain of apathy, anorexia, restlessness and generalized weakness. Prolonged deficiency leads to beriberi and/or Wernicke’s encephalopathy. The most common presenting symptom of thiamine deficiency is a pins-and-needles feeling in one’s extremities despite normal vitamin B12 and folate.

The average time from surgery to onset of thiamine deficiency symptoms was 9 months. Persistent vomiting, alcoholism, and non-compliance with vitamins are all contributing factors to thiamine-B1 deficiency.

Treatment for those suspected of thiamine-B1 deficiency: 50-100mg of thiamine twice daily.

https://www.soard.org/article/S1550-7289(11)00050-5/fulltext

Edited August 20, 20187 yr by Missouri-Lee's Summit

I suspect that at least of part of this is from the popularity of low carb dieting, as grains are one of the major sources of B1, and even for those who aren't big into Atkins, keto, etc., grain products tend to be but on the back burner for quite a while in favor of protein (a necessity) and green vegetables.

1 hour ago, RickM said:

I suspect that at least of part of this is from the popularity of low carb dieting, as grains are one of the major sources of B1, and even for those who aren't big into Atkins, keto, etc., grain products tend to be but on the back burner for quite a while in favor of Protein (a necessity) and green vegetables.

Not always, sometimes its about absorption capabilities. I am deficient in b1, (and other vitamins) but I knew I would be, I cannot absorb many vitamins through my digestive system. No clue why. Don't even care. I have to get the ones i can through IV infusions. The others that are not offered through infusion, i have to just keep supplementing orally and hope the levels rise enough to stave off issues.

Been this way since forever. Even when I was a "carbaterian" lol

8 hours ago, GreenTealael said:

Not always, sometimes its about absorption capabilities. I am deficient in b1, (and other vitamins) but I knew I would be, I cannot absorb many Vitamins through my digestive system. No clue why. Don't even care. I have to get the ones i can through IV infusions. The others that are not offered through infusion, i have to just keep supplementing orally and hope the levels rise enough to stave off issues.

Been this way since forever. Even when I was a "carbaterian" lol

Certainly, there are no end of idiosyncratic dietary quirks that we can, as individuals, have - my wife is chronically low on potassium, which has nothing to do with her WLS (it's just her.) My thoughts on the thiamin issue is that is seems like they may be trying to pinpoint a surgical cause, whereas they may well be chasing a dietary/social issue.