Vitamins and Their Functions Quiz

Vitamins: Biochemical Roles

• "VITAMIN" means "vital for life"
• Vitamins are Micronutrients (Nutrients required in very small amounts - mg or µg), necessary for everyday healthy functioning of the body
• Vitamins cannot be synthesized in the body, so they must be supplied through diet
• Vitamins are essential components of healthy diets and play important roles in cellular metabolism
• Although present in small amounts within cells, they are critically important
• Deficiency in vitamins can lead to various diseases

What are Vitamins?

• Non-caloric organic nutrients
• Facilitate body processes like digestion, absorption, metabolism, and growth
• Some vitamins exist in food as precursors or provitamins
• The term "vitamin" was initially used to describe a "vital amine" (thiamine, B1), crucial to preventing beriberi disease (once common in people relying on white rice).

Vitamins and Coenzymes

• Vitamins often function as coenzymes
• Coenzyme: a small molecule that works with an enzyme to promote its activity
• A coenzyme tightly bound to an enzyme protein is a prosthetic group
• A complete, catalytically active enzyme with its bound coenzyme is a holoenzyme
• The protein part of this enzyme is the apoenzyme or apoprotein

Vitamin Intake and Measurement

• Humans need at least 12 vitamins
• A balanced diet generally provides sufficient levels, but supplementation is common
• Most vitamins undergo chemical alteration to function correctly in the body
• Some vitamins are measured in International Units (IUs), a measure of biological activity
• This system is necessary because certain vitamins are present in various natural forms, each with slightly different effects at equal weight.
• Other vitamins are measured by weight (mg or µg)

Vitamins - US FDA Recommendations

• The Food and Drug Administration (FDA) sets Daily Reference Intakes (DRIs) in the US
• DRIs are a set of values, including Estimated Average Requirements (EARs), Recommended Dietary Allowances (RDAs), Adequate Intakes (AIs), and Tolerable Upper Intake Levels (ULs)
• These values represent the daily intake needed by 95% of the population.

Vitamin Categories

• Vitamins are categorized into water-soluble and fat-soluble groups
• Water-soluble vitamins: The "B" vitamins (Pantothenic acid, Biotin, Folic acid...), Vitamin C
• Fat-soluble vitamins: Vitamins A, D, E, K

Water-soluble vs. Fat-soluble Vitamins

• Water-soluble: Cannot be stored in the body, and excess is excreted in urine. Unstable to heat and light; leach into cooking liquids.
• Fat-soluble: Can be stored in the body; regular supply isn't needed. Can accumulate to toxic levels if large amounts are ingested. Stable at normal cooking temperatures.

Water-soluble Vitamins (Details)

• Found in vegetables, fruits, grains, and meats
• Absorbed directly into the blood stream
• Not stored in the body; toxicity is infrequent.
• Alcohol, smoking could decrease absorption.
• Dissolve in water, subject to cooking losses, generally readily excreted
• 50-90% of B vitamins are absorbed, marginal deficiencies are more common
• Function as coenzymes; involved in energy metabolism

B-Vitamins (Specifics)

• This group of 8 vitamins acts as coenzymes and are crucial for cell function
• Includes: Thiamin (B1), Riboflavin (B2), Niacin (B3), Pantothenic Acid (B5), Pyridoxine (B6), Biotin (B7), Folic Acid (B9), and Cyanocobalamine (B12)

Vitamin C

• Ascorbic acid; toxic to some viruses, bacteria, and some malignant tumor cells. It is an antioxidant
• Protects the body from free radicals
• Aids in wound healing; formation of connective tissue (Collagen).
• Assists iron absorption. Maintains gum health. Enhances immunity.
• Prevention of heart disease and cancer

Vitamin C-Harmful Effects of Excess Intake

• Large doses (over 1000 mg) might negatively affect teeth and potentially cause diarrhea.

Vitamin B-1 (Thiamin)

• Involved in energy production from carbohydrates, nerve function, appetite, and growth
• Deficiency includes loss of appetite, weariness, and insomnia; possibly leading to beriberi disease.
• Sources: Fish, Liver, Legumes, nuts, whole grain breads

Vitamin B-2 (Riboflavin)

• Crucial for energy production; metabolism of carbohydrates, fats, and proteins. Also crucial for bone and tooth development.
• Cell respiration, antibody and red blood cell formation, vision, skin, nails, and hair health
• Sources: Milk, Eggs, Meats, Leafy Greens, Enriched Grains

Vitamin B-3 (Niacin)

• Involved in energy production, skin and tongue health, circulation, nervous system maintenance, digestion, and lowers cholesterol in high doses.
• Deficiency can cause Pellegra (4 D's - Dermatitis, Diarrhea, Dementia, and Death).
• Sources: Milk, Eggs, Meats, Leafy Greens, Enriched grains

Vitamin B6 (Pyridoxine)

• Crucial part of coenzyme needed in amino acid and fatty acid metabolism (converts tryptophan to niacin and serotonin) and for red blood cell formation.
• Deficiency might cause anemia, depression, and seizures.
• Sources: Meats, fish, poultry, liver, legumes, fruits, potatoes, whole grains

Vitamin B9 (Folate)

• Participates in new cell synthesis.
• Deficiency can lead to anemia (large-cell type).
• Sources: Asparagus, avocados, leafy vegetables, legumes, seeds, liver, breads,

Vitamin B12 (Cobalamin)

• Crucial for new cell synthesis and maintaining nerve cells.
• Deficiency causes anemia (large-cell type). Nerve degeneration.
• Sources: Animal products (meat, fish, poultry, milk, eggs)

Vitamin B5 (Pantothenic Acid)

• Part of coenzymes essential for energy metabolism.
• Deficiency symptoms can include vomiting, intestinal distress, insomnia, fatigue.

Vitamin B7 (Biotin)

• A cofactor in reactions related to energy metabolism, fat synthesis, amino acid metabolism, and glycogen synthesis.
• Deficiency may cause hair loss or skin rashes
• Widespread in food groups

Vitamin A (Retinol)

• Helps maintain vision, skin and mucous membranes, and bone and tooth growth
• Deficiency can cause vision problems (night blindness).
• Sources: Found in liver, eggs, dairy products and yellow/orange vegetables.

Vitamin D

• Acts as a hormone to regulate calcium uptake, helping promote calcium-binding protein synthesis
• Synthesized through UV light interaction with the skin.
• Deficiency results in rickets, where bones become soft and flexible.
• Sources: exposure to sunlight, fortified milk, margarine, liver, and some fish

Vitamin E

• Antioxidant and protects cell membranes
• Deficiency may cause male infertility in rats
• Sources: plant oils, wheat germ, nuts, seeds, and leafy greens

Vitamin K

• Crucial for blood coagulation and bone mineralization.
• Deficiency may lead to bleeding problems
• Sources: Leafy greents green vegetables, cabbage-type vegetables, soy products

Fat-soluble Vitamins

• Found in fats and oils
• Absorbed with fats into lymphatic system, carried in blood via transporters (chylomicrons).
• Stored in liver and fatty tissues
• High doses can be toxic
• Vitamins: A, D, E, and K.

Test your knowledge on vitamins and their essential roles in the human body. This quiz covers various aspects of vitamin functions, deficiencies, and dietary sources. Challenge yourself with questions related to B vitamins and their significance in health.