Role of vitamins in gastrointestinal diseases

Table 1 Major characteristics of the known vitamins

Vitamin	Recommended daily doses1	Major dietary sources	Deficiency syndromes	Tolerable daily upper intake levels
A	M: 900 μg	Orange, ripe yellow fruits, leafy vegetables, carrots, pumpkin, liver, soy milk, milk, sweet potatoes, butter, egg yolk	Night-blindness	3000 mcg
(Retinol, Carotenoids)	F: 700 μg		Hyperkeratosis, keratomalacia
B1 (Thiamine)	M: 1.2 mg	Whole grains, dried beans, oatmeal, brown rice, potatoes, pork, liver	Beriberi - dry (peripheral neuropathy) or wet (heart failure), Wernicke encephalopathy	ND
	F: 1.1 mg
B2 (Riboflavin)	M: 1.3 mg	Dairy products, bananas, popcorn, green beans, asparagus, dark green leafy vegetables	Rare	ND
	F: 1.1 mg		Non-specific symptoms
B3 (Niacin, Nicotinic acid)	M: 16.0 mg	Meat, fish, eggs, mushrooms, tree nuts, peas, bran	Pellagra	35 mg
	F: 14.0 mg
B5 (Pantothenic acid)	5.0 mg	Fortified cereals, Salmon, Meat, broccoli, avocados	Paresthesia, “burning feet”, GI symptoms	ND
B6 (Pyridoxine)	1.3-1.7 mg	Meat, liver, tree nuts, bananas, salmon, tuna, brown rice, potatoes	Anemia, peripheral neuropathy, insomnia, seborrheic dermatitis, stomatitis	100 mg
B7 (Biotin)	30.0 μg	Raw egg yolk, liver, peanuts, certain vegetables	Dermatitis, enteritis	ND
B9 (Folic acid)	400 μg	Spinach, enriched rice, fortified cereal, liver, avocado, lentils	Megaloblastic anemia	1000 mcg
			Neural tube defects
B12 (Cobolamine)	2.4 μg	Meat, salmon, egg yolk, lentils, spinach	Megaloblastic/Pernicious anemia	ND
C (Ascorbic acid)	M: 90 mg	Citric fruits, papaya, broccoli, strawberries, paprika, liver	Scurvy	2000 mg
	F: 75 mg
D (Cholecalciferol, Ergocalciferol)	15 μg	liver, mushrooms, fatty fish, milk, egg yolk, fortified cereals	Rickets and osteomalacia	100 mcg (4000 IU)
	(> 70 yr: 20 μg)	1 cup of milk = 50 IU; 30 min of sunlight = 10000 IU
E (Tocopherols)	15.0 mg	Sunflower seeds, almonds, fortified cereals, spinach, turnip greens	Very rare; mild hemolytic anemia, ataxia, neural degeneration	1000 mg
K (phylloquinone, menaquinones)	M: 120 μg	Leafy green vegetables, egg yolks, liver, mustard greens, asparagus, kiwi, dried prunes	Bleeding diathesis	ND
	F: 90 μg

¹In adults, not pregnant nor lactating. ND: Not determinable.

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.