The Water-Soluble Vitamins

B Vitamins and Vitamin C

The Vitamins

• Vitamins vs carbohydrates, fats, and proteins –Structure –Function –Food contents

The Vitamins

• Bioavailability • Precursors • Organic nature

The Vitamins

• Solubility • Toxicity

The Vitamins

The Vitamins

The B Vitamins

• Coenzymes

Thiamin

• Other names:

Vitamin B 1

• 1998 RDA – men:

1.2 mg/day

– women: 1.1 mg/day • Chief functions in the body – Part of coenzyme TPP (thiamin pyrophosphate) used in

energy metabolism

Thiamin

• Significant sources – Whole grain, fortified, or enriched grain products – Moderate amounts in all nutritious food – Pork • Easily destroyed by heat

– Beriberi

Thiamin

• Deficiency disease • Wet, with edema • Dry, with muscle wasting • Deficiency symptoms – Enlarged heart, cardiac failure – Muscular weakness – Apathy, poor short-term memory, confusion, irritability – Anorexia, weight loss • Toxicity symptoms: none reported

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Thiamin Sources

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Riboflavin

• Other names: Vitamin B 2 • 1998 RDA – Men:

1.3 mg/day

– Women: 1.1 mg/day • Chief functions in the body – Part of coenzymes FMN ( flavin mononucleotide

metabolism.

) and FAD (flavin adenine dinucleotide) used in energy

Riboflavin

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Riboflavin

• Significant sources – Milk products (yogurt, cheese) – Enriched or whole grains – Liver • Easily destroyed by ultraviolet light and irradiation

Riboflavin

• Deficiency disease: ariboflavinosis • Deficiency symptoms – Inflamed eyelids and sensitivity to light, reddening of cornea – Sore throat – Cracks and redness at corners of mouth – Painful, smooth, purplish red tongue – Inflammation characterized by skin lesions covered with greasy scales • Toxicity symptoms: none reported

Riboflavin Sources

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• Other names

Niacin

– Nicotinic acid – Nicotinamide – Niacinamide – Vitamin B 3 • Precursor: dietary tryptophan • 1998 RDA – Men:

16 mg NE/day

– Women: 14 mg NE/day • Upper level for adults: 35 mg/day

Niacin

• Chief functions in the body – Part of coenzymes NAD ( nicotinamide adenine dinucleotide ) and NADP (its phosphate form) used in energy metabolism • Significant sources – Milk, eggs, meat, poultry, fish – Whole-grain and enriched breads and cereals – Nuts – All protein-containing foods

Niacin

• Deficiency disease: pellagra • Deficiency symptoms – Diarrhea, abdominal pain, vomiting – Inflamed, swollen, smooth, bright red tongue – Depression, apathy, fatigue, loss of memory, headache…similar to raising some children, or attending college!

Bilateral symmetrical rash (sunlight exposure) of pellagra can be disturbing!

Niacin

• Toxicity symptoms – Painful flush, hives, and rash (“ niacin flush ”) – Excessive sweating – Blurred vision – Liver damage, – impaired glucose tolerance

Niacin Sources

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Biotin

• 1998 adequate intake (AI) – Adults:

30



g/day

• Chief functions in the body – Part of a coenzyme used in

energy metabolism

synthesis , fat synthesis, amino acid metabolism, and glycogen • Significant sources – Widespread in foods – Organ meats, egg yolks, soybeans, fish, whole grains – Also produced by GI bacteria!

Biotin

• Deficiency symptoms – Depression, lethargy, hallucinations, numb or tingling sensation in the arms and legs – Red, scaly rash around the eyes, nose, and mouth – Hair loss • Toxicity symptoms: none reported

Pantothenic Acid

• 1998 adequate intake (AI) – Adults:

5 mg/day

• Chief functions in the body – Part of coenzyme A , used in

energy metabolism

• Significant sources – Widespread in foods – Organ meats, mushrooms, avocados, broccoli, whole grains • Easily destroyed by food processing

Pantothenic Acid

• Deficiency symptoms – Vomiting, nausea, stomach cramps – Insomnia, fatigue, depression, irritability, restlessness, apathy – Hypoglycemia, increased sensitivity to insulin • Toxicity symptoms: none reported

Vitamin B 6

• Other names – Pyridoxine – Pyridoxal – Pyridoxamine • 1998 RDA – Adults (19-50 years):

1.3 mg/day

• Upper level for adults: 100 mg/day

Vitamin B 6

• Chief functions in the body – Part of coenzymes PLP (pyridoxal phosphate) and PMP (pyridoxamine phosphate) used in

amino acid and fatty acid metabolism

– Helps to convert tryptophan to niacin and to serotonin (a brain hormone) – Helps to make red blood cells!

Vitamin B 6

• Significant sources – Meats, fish, poultry – Potatoes, legumes, non-citrus fruits – Fortified cereals – Liver – Soy products • Deficiency symptoms – Scaly dermatitis – Anemia (small-cell type) – Depression, confusion, abnormal brain wave pattern, convulsions

Vitamin B 6

• Toxicity symptoms – Depression, fatigue, irritability, headaches – Nerve damage causing numbness and muscle weakness leading to an inability to walk and convulsions – Skin lesions

Vitamin B 6 Sources

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Folate: In Summary

• Other names – Folic acid – Folacin – Pteroylglutamic acid (PGA) • 1998 RDA – Adults:

400



g/day

• Upper level for adults: 1000  g/day

Folate

• Recommendations –Dietary folate equivalents (DFE) –Synthetic is 1.7 fold more powerful than the natural!

• Also, folate activation needs vitamin B 12

Folate: In Summary

• Chief functions in the body – Part of coenzymes THF (tetrahydrofolate) and DHF (dihydrofolate) used in DNA synthesis and therefore important in new cell formation • Significant sources – Fortified grains – Leafy green vegetables, legumes, seeds – Liver

Folate: In Summary

• Deficiency symptoms – Anemia (large-cell type) – Smooth, red tongue – Mental confusion, weakness, fatigue, irritability, headache • Toxicity symptoms – Masks vitamin B 12 -deficiency symptoms

Folate

• Neural tube defects –Spina bifida

Folate

• Heart disease • Cancer

Folate Sources

Vitamin B 12 : In Summary

• Other names:

cobalamin

(and related forms) • 1998 RDA – Adults:

2.4



g/day

• Chief functions in the body – Part of coenzymes methylcobalamin and deoxyadenosylcobalamin used in

new cell synthesis

– Helps to maintain nerve cells – Reforms folate coenzyme – Helps to

break down some fatty acids and amino acids

Vitamin B 12 : In Summary

• Significant sources – Animal products (meat, fish, poultry, shellfish, milk, cheese, eggs) – Fortified cereals • Easily destroyed by microwave cooking • Deficiency disease: pernicious anemia

Vitamin B 12

• Deficiency of folate or B 12

pernicious anemia

produces

Vitamin B 12 : In Summary

• Deficiency symptoms – Anemia (large-cell type) – Fatigue, degeneration of peripheral nerves progressing to paralysis • Toxicity symptoms: none reported

Non-B Vitamins

• Choline

Non-B Vitamins

• Inositol • Carnitine • Vitamin imposters

Metabolic Pathways Involving B Vitamins

The B Vitamins

• B vitamin deficiencies –Glossitis-swollen tongue!

–Cheilosis-ulceration near mouth • B vitamin toxicities from common food sources???

• Let’s see…

How much to eat to be toxic??

• A vitamin supplement or… • 3000 bananas!!

How about 6000 cups of rice!!

Or 3600 chicken breasts!

>10,000 hot wings!!

Vitamin C

Vitamin C

Vitamin C

• Other name: ascorbic acid • 2000 RDA – Men: 90 mg/day – Women: 75 mg/day – Smokers: + 35 mg/day • Upper level for adults: 2000 mg/day

Vitamin C

• Chief functions in the body – Collagen synthesis • Strengthens blood vessel walls, forms scar tissue, provides matrix for bone growth – Antioxidant – Thyroxin synthesis-helps prevent goiter – Amino acid metabolism – Strengthens resistance to infection – Helps in absorption of iron

Vitamin C

• Significant sources – Citrus fruits – Cabbage-type vegetables, dark green vegetables (such as bell peppers and broccoli) – Cantaloupe, strawberries – Lettuce, tomatoes, potatoes – Papayas, mangoes • Easily destroyed by heat and oxygen

Vitamin C

• Deficiency disease: scurvy • Deficiency symptoms – Anemia (small-cell type) – Atherosclerotic plaques – Pinpoint hemorrhages, bone fragility, joint pain – Poor wound healing, frequent infections, bleeding gums, loosened teeth – Muscle degeneration and pain, hysteria, depression, rough skin, blotchy bruises

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Vitamin C

• Toxicity symptoms – Nausea, abdominal cramps, diarrhea – Headache, fatigue, insomnia – Hot flashes, rashes – Interference with medical tests, aggravation of gout symptoms, urinary tract problems, kidney stones

Vitamin C Sources

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Vitamin And Mineral Supplements

• Arguments for supplements –Correct overt deficiencies –Improve nutrition status –Reduce disease risks –Support increased nutrient needs –Improve the body’s defenses

Vitamin And Mineral Supplements

• Who needs supplements?

Arguments for Supplements

• Who Needs Supplements?

– People with nutritional deficiencies – People with low energy intake – less than 1600 kcalories per day – Vegans and those with atrophic gastritis need vitamin B 12 – People with lactose intolerance, milk allergies, or inadequate intake of dairy foods © 2008 Thomson - Wadsworth

Arguments

for

Supplements

• Who Needs Supplements?

– People in certain stages of the life cycle • Infants need iron and fluoride • Women of childbearing age need folate • Pregnant women need folate and iron • Elderly need vitamins B 12 and D – People with diseases, infections, or injuries, and those who have had surgery that affects nutrient digestion, absorption or metabolism – People taking medications that interfere with the body’s use of specific nutrients © 2008 Thomson - Wadsworth

Vitamin And Mineral Supplements

• Arguments against supplements –Toxicity –Life-threatening misinformation –Unknown needs –False sense of security –Other invalid reasons

Arguments against Supplements

• Other Invalid Reasons: – Belief that food supply and soil contain inadequate nutrients – Belief that supplements provide energy – Belief that supplements enhance athletic performance or lean body mass without physical work or faster than work alone – Belief that supplements will help a person cope with stress – Belief that supplements can prevent, treat or cure conditions

Selection of Supplements

• What form do you want?

• What vitamins and minerals do you need?

– Do not exceed Tolerable Upper Intake Levels.

– Be careful about greater that 10 mg of iron.

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Selection of Supplements

• Are there misleading claims?

– Ignore organic or natural claims.

– Avoid products that make high potency claims.

– Watch fake preparations.

– Be aware of marketing ploys. – Be aware of preparations that contain alcohol.

– Be aware of the latest nutrition buzzwords.

– Internet information is not closely regulated.

• What about the cost? – Local or store brands may be just as good as nationally advertised brands.

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Regulation of Supplements

• Nutritional labeling for supplements is required.

• Labels may make nutrient claims according to specified criteria.

• Labels may claim that lack of a nutrient can cause a deficiency disease and include the prevalence of that disease.

• Labels may make health claims that are supported by significant scientific agreement.

© 2008 Thomson - Wadsworth

Vitamin And Mineral Supplements

• Bioavailability • Antagonistic actions

Vitamin And Mineral Supplements

• Selection of supplements –Form –Contents –Misleading claims –Cost

Vitamin And Mineral Supplements

• Regulation of supplements

An Example of a Supplement Label