Water-Soluble Vitamins Jamie Pope, Steven Nizielski, and Alison McCook NUTRITION for a Changing World FIRST EDITION Chapter 11 Water-Soluble Vitamins It’s Not a Germ © 2016 by W. H. Freeman and Company & Scientific American

Chapter 11 Objectives Describe the general properties of the water-soluble vitamins and proper handling techniques Describe the possible causes of a vitamin deficiency Describe the role of vitamins as coenzymes List two excellent food sources of each of the water-soluble vitamins Identify the vitamin deficiencies that cause megaloblastic anemia, and explain how this anemia occurs Identify the vitamins that have neurological functions, act as an antioxidant, or are involved in energy metabolism, red blood cell production, and DNA and RNA synthesis

Mysterious Epidemic 1914: epidemic in the southern US Signs and symptoms: scaly skin, mouth sores, diarrhea, confusion, and ultimately mental deterioration In 1915, he conducted a study on inmates Implicated diet as the cause Prisoners had niacin deficiency In 1914 he US Surgeon General asked Dr. Goldberger to investigate a mysterious epidemic, known at that time as mal de rosa, sweeping across the American South. Forty percent of those acquiring the disease died. Doctors believed it was a infectious disease caused by an as-yet-unidentified microbe. Dr. Goldberger wasn’t convinced, as it afflicted poor people, not wealthy people, and prisoners but not guards. A germ wouldn’t make sociological distinction. He believed it was caused by diet, as the ill people tended to eat diets consisting of cornbread, molasses, and a little pork fat. In 1915 he conducted a study on 11 inmates in a Mississippi prison who volunteered to participate in exchange for a pardon. He fed them a corn-based, less-nutritious diet, and within five months, six of the men showed signs of pellagra, whereas other inmates on a diet that was more nutritious did not.

Water-Soluble Vitamins Organic compounds Include Eight B vitamins Vitamin C Choline

Preserving Vitamins in Foods

Possible Causes of Vitamin Deficiencies

B Vitamins Most are coenzymes in energy metabolism They are Thiamin (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5) Pyridoxine (B6) Biotin (B7) Folate (B9) Cobalamin (B12)

B Vitamins Function as Coenzymes

Thiamin (Vitamin B1) Functions Coenzyme form in energy metabolism Synthesis of RNA and DNA Production of neurotransmitters

Food Sources of Thiamin

Thiamin Deficiency Beriberi Wernicke-Korsakoff syndrome Causes muscle wasting, fatigue, and mental disturbances Wernicke-Korsakoff syndrome Causes severe neurological disturbances Alcohol decreases thiamin absorption, increases excretion in the urine, decreases storage in the liver, and decreases conversion of thiamin into its coenzyme In the e1800s a painful degenerative disease called beriberi was sweeping East Asia because of the new technology to refine rice. The hulls of the rice were removed and discarded to increase shelf life. Removing the hull also removed many essential nutrients. Beriberi is rare in developed countries because of the enrichment of grains. As many as 80% of alcohol abusers encounter another form of thiamin deficiency called Wernicke-Korsakoff syndrome.

Niacin (Vitamin B3) Functions Energy metabolism Synthesis of glucose, fatty acids, cholesterol, and steroid hormones DNA repair Cell signaling Regulation of gene expression

Niacin Food Sources Found in meats Synthesized from the amino acid tryptophan Dietary recommendations given in niacin equivalents (NE)

Food Manufacturers Fortify or Enrich Flour Fortified Enriched

Niacin Deficiency Pellagra Symptoms Fatigue, diarrhea, mental deterioration, death

Niacin Toxicity Supplements Therapeutic Flushing, gastrointestinal effects, liver damage Therapeutic Lower cholesterol Need monitoring by medical provider

Riboflavin (Vitamin B2) Function Helps with energy metabolism

Food Sources of Riboflavin Found in milk and dairy products Destroyed by UV light

Riboflavin Deficiency Ariboflavinosis Symptoms: cracks and redness of the lips and corners of the mouth, swelling of the mouth and sore throat

Pyridoxine (Vitamin B6) Functions Acts as coenzyme in the release of glucose from glycogen Metabolizes tryptophan to niacin Helps in production of hemoglobin and neurotransmitters

Food Sources of Vitamin B6 (Pyridoxine)

Vitamin B6 Deficiency Anemia Impaired immune function Weakness Dermatitis Neurological disorders

Vitamin B6 Toxicity Supplements above the UL Pain and numbness Sometimes irreversible neurological effects

Pantothenic Acid Functions Food sources Helps with energy metabolism Synthesizes fatty acids, cholesterol, steroid hormones, and two neurotransmitters Food sources Widespread in virtually all foods Deficiency rare

Folate Functions Acts as coenzyme in metabolism of certain amino acids Helps in DNA and RNA synthesis Helps with normal cell division and development

Folate Equivalents

Folate Equivalents

Folate Food Sources

Folate Deficiency Can cause megaloblastic anemia In pregnancy there is increased risk of neural tube defects

Folate Toxicity UL for synthetic forms of folic acid: 1,000 mcg/d Masks vitamin B12–deficiency symptoms

Cobalamin (Vitamin B12) Absorption Functions Requires acid and intrinsic factor Functions Acts as coenzyme for deriving energy from amino acids and for converting homocysteine to methionine Maintains neural sheaths

Food Sources of Vitamin B12

Vitamin B12 Deficiency Megaloblastic anemia Called pernicious anemia if because of lack of intrinsic factor Cognitive impairment and problems with motor control

Choline Functions Choline deficiency Excessive intake Intertwined with function of folate and vitamin B12 Forms neurotransmitter, acetylcholine Is part of phospholipids in cell membranes Choline deficiency Liver damage Excessive intake Only through supplementation Fishy body odor

Vitamin C (Ascorbic Acid) Functions Acts as coenzyme in biological reactions Aids in hormone production Involved in collagen synthesis Is an antioxidant

Food Sources of Vitamin C

Vitamin C Deficiency Scurvy

Vitamin C Toxicity UL = 2,000 mg May cause Diarrhea Bloating Increase risk of kidney stones

Functions of Water-Soluble Vitamins

Summary The essential water-soluble vitamins disperse easily in water-based solutions and include the B vitamins, vitamin C, and the vitaminlike nutrient choline Water-soluble vitamins are not stored in large quantities in the body and must be consistently consumed in adequate amounts in order to meet the body’s needs and prevent deficiencies Disease from dietary deficiency of water-soluble vitamins results from inadequate intake or conditions that decrease absorption with subsequent low blood levels; although deficiency of the many B vitamins may have similar signs and symptoms and often occur simultaneously, unique deficiency diseases have been identified for many of the B vitamins and vitamin C

Summary (Cont’d) Although water-soluble vitamins rarely reach toxicity levels from food alone, excess intake through dietary supplements and/or fortified foods may exceed the established tolerable upper intake levels (UL) for some vitamins The B vitamins include thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), cobalamin (B12), and folate (B9) The B vitamins function primarily as coenzymes, chemical compounds that bind enzymes and are required for their function or activity; as coenzymes, they participate in energy metabolism, transforming carbohydrates, protein, and fat into energy, as well as a myriad of other types of reactions

Summary (Cont’d) Megaloblastic anemia—characterized by large, immature, and sometimes irregularly shaped red blood cells—results from folate deficiency but is also seen with vitamin B12 deficiency Choline, the most recently identified essential nutrient, is a water-soluble compound frequently grouped with the B vitamins because of its intertwined role with folate and vitamin B12 Vitamin C is a water-soluble vitamin which functions as a coenzyme in biological reactions, aids in hormone production, serves as an antioxidant, and is involved in the synthesis of collagen