Water-Soluble Vitamins Overview

• Nine water-soluble vitamins:

  • Vitamin C and 8 B-complex vitamins

    • Thiamin

    • Riboflavin

    • Niacin

    • Pantothenic acid

    • Vitamin B6

    • Biotin

    • Folate

    • Vitamin B12

Characteristics

• Heat and Light Sensitivity: Easily destroyed by heat, light, and oxidation. Proper storage and minimal cooking are necessary to preserve their integrity.

• Absorption and Excretion

  • Absorption: Primarily absorbed in the small intestine.

  • Hydrophilic: These vitamins are water-soluble.

  • Transport: Transported directly into the bloodstream.

  • Storage: Not stored in significant amounts, thus need to be consumed daily.

  • Excretion: Excess amounts are excreted in urine, reducing toxicity risk.

Functions

B Vitamins

• Coenzymes: Act as coenzymes in metabolic processes, crucial for energy production from carbohydrates, proteins, and fats.

Vitamin C

• Antioxidant: Protects cells from oxidative stress.

• Iron Absorption: Enhances non-heme iron absorption from plant-based foods.

• Immune Support: Supports various cellular functions of the immune system/protects immune system/reduces risk of chronic diseases

Specific Vitamins and Their Functions

Thiamin (Vitamin B1)

• Functions:

  • ATP Production: Essential for energy metabolism, converting carbohydrates into ATP.

  • Nerve Function: Necessary for nerve impulse transmission.

• Deficiency Risk: A deficiency of Vitamin B1 leads to Beriberi and Wernicke-Korsakoff

  • Wet Beriberi: Affects cardiovascular system; symptoms include rapid heart rate, shortness of breath, and leg swelling.

  • Dry Beriberi: Affects nervous system; symptoms include numbness, muscle weakness, and paralysis.

  • Wernicke-Korsakoff Syndrome: Neurological disorder due to thiamin deficiency, commonly seen in alcoholics; symptoms include confusion, memory loss, and loss of muscle coordination.

Riboflavin (Vitamin B2)

• Functions:

  • Energy Metabolism: Part of coenzymes FMN and FAD involved in oxidation-reduction reactions.

  • B Vitamin Function: Enhances the function of other B vitamins (B6 and niacin).

• Deficiency: A deficiency of Vitamin B2 leads to Ariboflavinosis

  • Ariboflavinosis: Symptoms include sore throat, redness and swelling of the mouth and throat, cracks at the corners of the mouth (cheilosis), and inflamed, magenta-colored tongue (glossitis).

Niacin (Vitamin B3)

• Functions: Helps with energy metabolism and skin and digestive health

  • Energy Metabolism: Part of coenzymes NAD and NADP involved in glucose, fat, and alcohol metabolism.

  • Skin and Digestive Health: Maintains healthy skin and digestive tract.

• Deficiency: A deficiency in Vitamin B3 leads to Pellagra

  • Pellagra: Characterized by the "four Ds":

    • Dermatitis: Inflammation of the skin.

    • Diarrhea: Gastrointestinal distress.

    • Dementia: Mental confusion and memory loss.

    • Death: If untreated, can be fatal.

Pantothenic Acid (Vitamin B5)

• Functions:

  • Coenzyme A: Vital for the synthesis and oxidation of fatty acids, and the metabolism of carbohydrates and proteins.

  • Cholesterol Synthesis: Involved in synthesizing cholesterol, steroid hormones, and neurotransmitters.

• Deficiency: A deficiency in Vitamin B5 is rare but has symptoms

  • Rare: Symptoms include fatigue, irritability, nausea, vomiting, muscle cramps, and hypoglycemia.

Biotin (Vitamin B7)

• Functions:

  • Coenzyme for Carboxylases: Essential for energy metabolism and the synthesis of fatty acids, isoleucine, and valine.

  • Gene Expression: Important for maintaining hair, skin, and nails health.

• Deficiency: A Deficiency in Vitamin B7 is rare but has symptoms

  • Rare: Symptoms include hair loss (alopecia), skin rashes (dermatitis), and neurological symptoms like depression, lethargy, and hallucinations.

Vitamin B6 (Pyridoxine)

• Functions:

  • Protein Metabolism: Involved in amino acid metabolism and glycogenolysis.

  • Neurotransmitter Synthesis: Crucial for the synthesis of neurotransmitters such as serotonin, dopamine, and GABA.

  • Hemoglobin Formation: Essential for the production of hemoglobin.

• Deficiency: A deficiency of Vitamin B6 leads to microcytic anemia and neuro symptoms

  • Microcytic Anemia: Small, pale red blood cells due to impaired hemoglobin synthesis.

  • Neurological Symptoms: Depression, confusion, and seizures in severe cases.

Folate (Vitamin B9)

• Functions:

  • DNA Synthesis and Repair: Essential for cell division and growth.

  • Amino Acid Metabolism: Converts homocysteine to methionine.

  • Prevention of Neural Tube Defects: Critical during pregnancy to prevent birth defects.

• Deficiency:

  • Macrocytic Anemia: Large, immature red blood cells due to impaired DNA synthesis.

  • Birth Defects: Increased risk of neural tube defects in newborns.

Vitamin B12 (Cobalamin)

• Functions:

  • Red Blood Cell Formation: Essential for the production of healthy red blood cells.

  • Nerve Function: Maintains myelin sheath around nerves.

  • DNA Synthesis: Involved in the synthesis of DNA and RNA.

• Deficiency: A deficiency in Vitamin B12 leads to pernicious anemia and neurological issues

  • Pernicious Anemia: A type of macrocytic anemia caused by the body's inability to absorb B12.

  • Neurological Issues: Symptoms include numbness, tingling in the hands and feet, memory loss, and cognitive decline.

Vitamin C (Ascorbic Acid)

• Functions:

  • Collagen Synthesis: Essential for the synthesis of collagen, a structural protein in connective tissues.

  • Antioxidant: Protects cells from damage by free radicals.

  • Iron Absorption: Enhances the absorption of non-heme iron from plant-based foods.

  • Immune Function: Supports the production and function of white blood cells.

• Deficiency: A deficiency in Vitamin C leads to Scurvy

  • Scurvy: Symptoms include bleeding gums, joint pain, weakness, anemia, and bruising due to impaired collagen synthesis.

Absorption and Storage

• Absorption: Occurs in the small intestine, with some vitamins requiring specific transport mechanisms.

• Storage: Limited storage capacity, with vitamin B12 being the exception, stored in the liver.

• Excretion: Excess vitamins are excreted in urine, which necessitates regular intake to avoid deficiencies.

Toxicity

• Low Toxicity Risk:

  • Generally, water-soluble vitamins are not toxic due to their excretion in urine.

  • However, excessive intake of supplements can sometimes cause adverse effects, such as:

    • Vitamin B6: High doses can cause nerve damage.

    • Niacin: Large doses can cause flushing, liver damage, and gastrointestinal issues.

    • Vitamin C: Excessive intake can lead to gastrointestinal disturbances and kidney stones.

Sources of Water-Soluble Vitamins

Thiamin (Vitamin B1)

• Food Sources:

  • Whole grains (brown rice, oats, barley)

  • Enriched and fortified grains and cereals

  • Pork

  • Legumes (beans and lentils)

  • Seeds and nuts (sunflower seeds, flaxseeds)

Riboflavin (Vitamin B2)

• Food Sources:

  • Dairy products (milk, yogurt, cheese)

  • Eggs

  • Lean meats (beef, chicken)

  • Green leafy vegetables (spinach, broccoli)

  • Enriched cereals and grains

  • Almonds

Niacin (Vitamin B3)

• Food Sources:

  • Meat (beef, pork, poultry)

  • Fish (tuna, salmon)

  • Enriched and fortified grains and cereals

  • Peanuts

  • Legumes (beans, lentils)

  • Mushrooms

Pantothenic Acid (Vitamin B5)

• Food Sources:

  • Whole grains

  • Avocados

  • Meats (chicken, beef)

  • Dairy products

  • Legumes (lentils, peas)

  • Eggs

  • Vegetables (broccoli, sweet potatoes)

Biotin (Vitamin B7)

• Food Sources:

  • Eggs (especially yolk)

  • Nuts and seeds (almonds, sunflower seeds)

  • Fish (salmon, tuna)

  • Whole grains

  • Legumes (soybeans, peanuts)

  • Bananas

  • Cauliflower

  • Mushrooms

Vitamin B6 (Pyridoxine)

• Food Sources:

  • Poultry (chicken, turkey)

  • Fish (salmon, tuna)

  • Potatoes

  • Bananas

  • Chickpeas

  • Fortified cereals

  • Nuts and seeds

Folate (Vitamin B9)

• Food Sources:

  • Leafy green vegetables (spinach, kale)

  • Citrus fruits (oranges, lemons)

  • Legumes (beans, lentils)

  • Avocados

  • Beets

  • Broccoli

  • Asparagus

  • Fortified grains and cereals

Vitamin B12 (Cobalamin)

• Food Sources:

  • Animal products (meat, poultry, fish)

  • Dairy products (milk, cheese, yogurt)

  • Eggs

  • Fortified foods (plant-based milk, cereals, nutritional yeast)

Vitamin C (Ascorbic Acid)

• Food Sources:

  • Citrus fruits (oranges, lemons, grapefruits)

  • Berries (strawberries, raspberries)

  • Melons (cantaloupe, watermelon)

  • Tomatoes

  • Bell peppers (red, green, yellow)

  • Green leafy vegetables (kale, spinach)

  • Broccoli

  • Brussels sprouts

  • Potatoes

Summary of Food Sources

• Whole Grains and Fortified Cereals: Rich in Thiamin, Riboflavin, Niacin, Pantothenic Acid, Biotin, and Folate.

• Animal Products: Key sources of Vitamin B12, Riboflavin, Niacin, Vitamin B6, and Pantothenic Acid.

• Legumes and Nuts: Good sources of Thiamin, Niacin, Biotin, Vitamin B6, and Folate.

• Fruits and Vegetables: Essential for Vitamin C, Folate, Biotin, and small amounts of other B vitamins.

Other Vitamin-Like Compounds

• Some compounds may not be classified as vitamins but are still essential to overall health.

• Often synthesized in adequate amounts in the body

• May become essential under certain circumstances, such as during illness or chronic disease

  • Ex: Include choline, carnitine, lipoic acid, and inositol

Choline

• Classification: Often grouped with B vitamins, but not officially a vitamin.

• Essential Nutrient: Necessary for liver function, normal brain development, nerve function, muscle movement, supporting energy levels, and maintaining a healthy metabolism.

Functions of Choline

• Cell Structure: Component of phospholipids, which are crucial for cell membranes.

• Methylation Reactions: Donates methyl groups for various biochemical reactions, including DNA methylation.

• Neurotransmitter Synthesis: Precursor to acetylcholine, a neurotransmitter involved in muscle control, memory, and mood.

• Lipid Transport and Metabolism: Involved in the transport and metabolism of fats and cholesterol.

Deficiency

• Symptoms:

  • Muscle damage

  • Liver damage

  • Nonalcoholic fatty liver disease (NAFLD)

  • Potential increased risk of neural tube defects in pregnancy

• At Risk Groups:

  • Pregnant women

  • People with genetic variations that increase choline needs

  • People with a high alcohol intake

Toxicity

• Upper Limit: Excessive intake can lead to symptoms such as:

  • Fishy body odor

  • Vomiting

  • Excessive sweating and salivation

  • Low blood pressure

  • Liver toxicity

Food Sources of Choline

• Animal Products:

  • Eggs (especially yolk)

  • Meat (beef, chicken)

  • Fish (salmon, cod)

  • Dairy products (milk, cheese)

• Plant-Based Sources:

  • Cruciferous vegetables (broccoli, Brussels sprouts)

  • Legumes (soybeans, peanuts)

  • Nuts and seeds

  • Whole grains

Recommended Intake of Choline

• Males: 550 mg/day

• Females: 425 mg/day

• Upper Limit: 3,500 mg/day

Summary

• Choline is an essential nutrient important for liver function, brain development, and the formation of acetylcholine.

• Deficiency can lead to liver damage and muscle damage, while excessive intake can cause fishy body odor and other symptoms.

• Food Sources include eggs, meat, fish, dairy, cruciferous vegetables, legumes, nuts, and seeds.

Carnitine, Lipoic Acid, and Inositol

Carnitine

• Function: Necessary for the proper utilization of fats.

• Major Food Sources: Meat and dairy products.

• Synthesis: Can be synthesized by the body.

Lipoic Acid

• Function: Helps cells generate energy; has potential antioxidant effects.

• Synthesis: Can be synthesized by the body.

Inositol

• Function: Maintains healthy cell membranes.

• Major Food Sources: Found in plant sources.

• Synthesis: Can be synthesized by the body.