After weight-loss surgery, some patients may experience a transient elevation in liver function tests that resolves over time. We have previously reported on this. IT is essential to distinguish between the Duodenal switch and the SIPS/SADI procedure, where some patients are led to believe they are identical. These procedures differ physiologically, and their weight loss and metabolic behaviours vary significantly.

Other than the stress of the weight loss, obesity, and comorbidities of obesity, there may be other anatomical post-surgical causes for elevated liver function test. This has also been discussed extensively.

A recent literature review supports the protective effects of vitamin D supplementation.

Effects of vitamin D supplementation on the glycaemic indices, lipid profile, and liver function tests in patients with cirrhosis: a double-­ blind randomised controlled trial

Low serum 25-hydroxyvitamin D levels are associated with liver injury markers in the US adult population

Exploring the Correlation Between Vitamin D Level and Serological Markers in Liver Diseases: Insights from a Cross-Sectional Study

Elevated liver enzymes may be caused by many factors, including nutritional deficiencies, excessive supplementation (turmeric), medications, alcohol, adhesions causing partial bowel obstruction, and increased enterohepatic bile reabsorption . I would be very cautious about associating vitamin D supplementation with elevated liver function test results, even if the vitamin D level is in the very high normal range, regardless of the  daily dose (much less frequent with injectable).

Vitamin D, as a fat-soluble vitamin, however, protects the liver and improves liver function test even in very high serum level . In rare cases, prolonged, elevated vitamin D levels may strain the liver. In Fact, the association of the vitamin D level and liver disease, including cirrhosis, leads to hepatocellular carcinoma (HCC) and dea h. Vitamin D protects the liver from HCC but cannot reduce the risk of cirrhosis.