The B-complex vitamins includes eight compounds that all play important roles in cellular metabolism and digestion. Within the digestive system, most of the B-vitamins are essential for producing stomach acids and maintaining muscle tone, especially the valves between the different segments, such as the ileocecal valve. B-vitamin deficiencies lead to reduced intestinal mobility, gastric secretions, appetite and impaired digestion. B-vitamins often co-exist within the same foods, such as organ meats, fish, wheat germ, legumes and green leafy vegetables.
Thiamine, or vitamin B-1, contributes to the production of energy by metabolizing carbohydrates, fats and proteins. Further, it contributes to the production of hydrochloric acid within the stomach, maintains muscle tone in the intestines and enhances normal appetite, according to “Vitamins: Fundamental Aspects in Nutrition and Health.” Recommended daily amounts of thiamine range from 0.2 mcg for infants under 6 months old to 2.8 mcg for lactating women. Deficiency leads to beriberi, which is a nervous system disorder, loss of appetite, severe weight loss, constipation and gastrointestinal disturbances, among other symptoms.
Riboflavin, or vitamin B-2, contributes to the production of energy by metabolizing carbohydrates, fats, proteins and ketone bodies. It also enhances the mucous membranes of the digestive tract. Recommended daily amounts of riboflavin range from 0.3 mg for infants under 6 months old to 1.6 mg for lactating women, according to “Advanced Nutrition: Macronutrients, Micronutrients, and Metabolism.” Deficiency leads to ariboflavinosis, which causes cracks and sores at the corner of the mouth and tongue inflammation, and poor digestion, among other symptoms.
Niacin, or vitamin B-3, is required for DNA repair, the production of steroid hormones, metabolism of food, gastric juice production and the secretion of bile, which is needed to digest fat, as cited in “Biochemistry of Human Nutrition.” Recommended daily amounts of niacin range from 2 mg in infants under six months old to 17 mg for lactating women. Deficiency leads to pellagra, which includes indigestion, diarrhea and appetite loss, among other symptoms.
Pantothenic acid, or vitamin B-5, is needed to synthesize coenzyme-A and metabolize proteins, carbohydrates and fats. It is also required for the functioning and peristalsis of the gastrointestinal tract. Recommended daily amounts of pantothenic acid range from 1.7 mg in infants under 6 months old to 7 mg for lactating women. Deficiency, although rare, can lead to numbness in the limbs and sluggish digestion.
Cobalamin, vitamin B-12, is required to build DNA, nerve tissue and red blood cells. Specifically, cobalamins are essential in the production of myelin, the protective sheath surrounding nerves that allows for electrical transmission of brain messages. Recommended daily amounts of cobalamin range from 0.4 mcg in infants under 6 months old, to 2.8 mcg for lactating women. Deficiency results in blood anemia, reduced brain functions and neuropathy, which includes reduced nerve transmissions to the gastrointestinal system, leading to constipation and compromised digestion, as cited in “Nutrition and Diagnosis-Related Care.” For vitamin B-12 to be absorbed from food in the intestines, a gastric protein known as intrinsic factor is needed.