Role of vitamins in gastrointestinal diseases

Table 2 Summary of the role of vitamins in gastrointestinal and liver diseases based on published intervention trials

Vitamin	Colorectal cancer	Other gastrointestinal malignancies	Inflammatory bowel disease	Chronic hepatitis C	Other
A	No role	No role	No role	Controversial (not enough data)	May improve chronic pancreatitis pain
B1	No data	No data	Improved IBD fatigue syndrome	No data	No data
B2	Probably protective (non-randomized trials)	No role	No data	No data	None
B6	Probably protective (non-randomized trials)	No role	No data	No data	Possible benefit in celiac disease
B9	Probably protective (non-randomized trials)	Probably protective for pancreatic cancer	No data	No data	Possible benefit in celiac disease
B12	No role	No role	No role	Probable adjunctive effect (one RCT)	Aphtous stomatitis
					Possible benefit in celiac disease
C	No role	Probable protective role in esophageal and pancreatic cancer	No role	No role	Prevention of gallstones
D	No role	Not protective against esophageal or pancreatic cancer	Inverse relation probable preventive and therapeutic effects	Additive effect to standard therapy (two RCTs)	Beneficial role in cholestatic liver diseases
E	No role	No role	No role	No data	Therapeutic role in non-alcoholic steatohepatitis
K	No role	Probably protective in HCC	No role	No role	None

No role: No evidence by currently available interventional trials; No data: No good quality interventional trials available; Most vitamins had an inverse relationship with the risk of CRC, however interventional trials failed to prove a beneficial preventive role. Probable role: Data from observational studies or inconsistent RCTs results.