Vitamins and Nutrition Overview Quiz

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Questions and Answers

What are the fat-soluble vitamins mentioned in the content?

B-complex vitamins and vitamin C

Vitamin C and vitamin B12

Vitamins A, D, E, and K (correct)

Vitamin A, B2, C, and D

Which of the following vitamins are classified as water-soluble?

Vitamin D and vitamin A

Vitamin A and vitamin D

Vitamin C and B-complex vitamins (correct)

Vitamin E and vitamin K

What are 'provitamins'?

Vitamins found only in animal sources

Natural isomers of vitamins

Vitamins that cannot be synthesized by the body

Precursors to vitamins (correct)

Why should popular science books on vitamins be avoided?

They often lack scientific accuracy. Signup and view all the answers

What does the term 'vitamer' refer to?

Different forms of a vitamin Signup and view all the answers

What is the measurement unit often used for vitamins in nutrition and medicine?

International units (IU) Signup and view all the answers

Which vitamin is NOT commonly discussed in the context of hypovitaminoses?

Vitamin B12 Signup and view all the answers

What is a key role of B-complex vitamins in the body?

Acting as enzyme cofactors Signup and view all the answers

Which form of vitamin D is produced by Mammalia through a photodependent pathway?

D3 Signup and view all the answers

What is the primary effect of hypovitaminosis D in children?

Rickets Signup and view all the answers

Which vitamin E vitamer is most commonly used in supplements for its stability?

α-tocopherol Signup and view all the answers

Which population is at a higher risk of hypovitaminosis D due to limited sunlight exposure?

Individuals with low body fat Signup and view all the answers

What is a recommended daily vitamin D intake for adults in the UK?

10 μg/day Signup and view all the answers

Which symptom is commonly observed during the early stages of hypovitaminosis D?

Clinical depression Signup and view all the answers

Which vitamin D vitamer is NOT acknowledged as a valid form?

D1 Signup and view all the answers

What condition in adults is referred to as osteomalacia which is associated with hypovitaminosis D?

Bone softening Signup and view all the answers

What condition is characterized by the development of an opaque cornea due to vitamin A deficiency?

Keratomalacia Signup and view all the answers

Which pigment is produced by halophilic Archaea and found in the red-pigmented feathers of greater flamingos?

Bacterioruberin Signup and view all the answers

What is the primary cause of nyctalopia?

Lack of rhodopsin Signup and view all the answers

Which vitamin is crucial for preventing neurological damage due to oxidative stress?

Vitamin E Signup and view all the answers

Which vitamin deficiency is linked to 500,000 children becoming blind each year?

Vitamin A Signup and view all the answers

What causes hypovitaminosis K and its related health issues?

Inability to recycle vitamin K Signup and view all the answers

What is the purpose of 'golden rice'?

To provide β-carotene in rice diets Signup and view all the answers

What role does vitamin C play in the body beyond acting as an antioxidant?

It acts as a cofactor for collagen biosynthesis Signup and view all the answers

What is the relationship between carotenoids and the Aves in the content provided?

Carotenoids are obtained from all three domains of life. Signup and view all the answers

Which of the following foods is rich in vitamin K2?

Goose meat Signup and view all the answers

What color are the feathers of Phoenicopterus ruber attributed to?

Echinenone Signup and view all the answers

Which group is known to oppose genetically modified crops like 'golden rice'?

Greenpeace Signup and view all the answers

What is the oxidized form of vitamin C?

Dehydroascorbic acid Signup and view all the answers

What can result from severe vitamin C deficiency?

Scurvy Signup and view all the answers

Which vitamin is particularly associated with bone density improvement when combined with vitamin D3?

Vitamin K2 Signup and view all the answers

What food is a significant source of vitamin E?

Rapeseed oil Signup and view all the answers

What is a common symptom of hypovitaminosis C?

Bleeding gums Signup and view all the answers

Which vitamin is essential for the production of NAD+ and NADP+?

Vitamin B3 Signup and view all the answers

Which of the following vitamins is almost never deficient in the diet?

Vitamin B5 Signup and view all the answers

What health issue can arise from a deficiency of vitamin B9 during pregnancy?

Neural tube defects Signup and view all the answers

Which vitamin is associated with the symptoms of ariboflavinosis?

Vitamin B2 Signup and view all the answers

What role does vitamin B6 play in the body?

Serving as an enzyme cofactor Signup and view all the answers

What can a deficiency of biotin lead to?

Skin rashes Signup and view all the answers

Which nutrient notably contributes to dry mouth and dental issues?

Vitamin C Signup and view all the answers

What enzyme cofactors are produced from vitamin B2?

FMN/FMNH2 and FAD/FADH2 Signup and view all the answers

Which vitamin A vitamer is critical for sperm production in Homo sapiens?

Retinoic acid Signup and view all the answers

What is hypervitaminosis B1 also known as?

Beriberi Signup and view all the answers

Which vitamin K vitamer is produced in the gut of Homo sapiens?

Vitamin K2 Signup and view all the answers

What is the primary role of both vitamin C and vitamin E in the cell?

Antioxidants Signup and view all the answers

What forms of vitamin B12 are found in the cytoplasm and mitochondria, respectively?

Methocobalamin and Adenosylcobalamin Signup and view all the answers

What wavelength range of light is necessary for vitamin D production?

290-315 nm Signup and view all the answers

Which provitamins are associated with vitamin A?

Carotenes and Retinyl esters Signup and view all the answers

Study Notes

Vitamins

Vitamins are organic molecules needed in small amounts for proper organism function.
Vitamin needs vary by organism.
Fat-soluble vitamins include A, D, E, and K.
Water-soluble vitamins include the B complex (9) and C.
Provitamins are precursors to vitamins.
Vitamers are different forms of a vitamin.
Vitamins are often measured in IU (International Units).
Chemical structures are shown for properties, not rote memorization.

Vitamins and Steroids - Cautions

Popular science books on vitamins often misrepresent the value of individual vitamins for treating conditions.
Proper understanding necessitates use of textbooks and peer-reviewed journal articles.
Chemical structures are shown for understanding properties, not rote memorization.

Vitamins and Steroids - Outline

Hypovitaminoses (vitamin deficiencies) are considered only for well-known conditions.
General terminology and groupings of vitamins A, D, E, and K are covered.
Detailed properties, sources, role in vivo, and provitamins/vitamers for these vitamins are included in the outline.

Definition and Groupings

Vitamins are organic molecules needed in small amounts for proper organism function.
Fats-soluble vitamins include A, D, E, and K - these are not created by the body and so must be consumed via diet.
Water-soluble vitamins include the B complex (9) and C - these are sometimes created by the body.
Provitamins are precursors to vitamins.

Fat-Soluble: Vitamin A

All vitamers are isoprenoids.
Important vitamers include: retinol, retinal, retinoic acid, retinyl esters.
Key for plant-derived and some animal-derived foods.
Retinal is needed for low-light vision and also found in some Archaea.
Retinoids are needed for sperm development and other processes.
Retinoic acid can reverse photoaging and is used to treat acne/cancer.
β-carotene, α-carotene, and γ-carotene are provitamins found in plants, used to create retinol in the body.
Retinyl palmitate is a common dietary form and storage form.
Consumption of Vitamin A above a prescribed level can be toxic.

Hypovitaminosis A

Xerophthalmia: thickening/hardening of the surfaces of the eyes.
Keratomalacia: inability of the eye to synthesize surface tissues, leading to an opaque cornea.
Nyctalopia: inability to see in low light, due to lack of retinaldehyde and thus rhodopsin in the retina.
Photophobia: aversion to bright light due to rhodopsin properties in retina.

Carotenoids in the Aves

Birds acquire carotenoids from their food source, which comes from all three domains (Bacteria, Archaea, and Eukarya).
Some notable pigments include Beta-carotene and astaxanthin.
Examples of carotenoids include bacterioruberin, echinenone, and astaxanthin which have red pigmentation.

Fat-Soluble: Vitamin D

Vitamins D are secosteroids (broken steroids) with notable vitamers: ergocalciferol (D2), cholecalciferol (D3), 22-dihydroergocalciferol (D4), sitocalciferol(D5).
They regulate calcium uptake in intestinal systems.
Insufficient vitamin D leads to rickets (bone softening), osteomalacia in adults, and osteoporosis.

Hypovitaminosis D

Rickets (children): Bone softening.
Osteomalacia (adults): Bone softening.
Osteoporosis: Bones become porous and fragile.
Clinical depression and clinical anxiety commonly found in hypovitaminosis D, along with other symptoms like muscular pain and muscle twitching.

Fat-Soluble: Vitamin E

Eight vitamers, four tocopherols and four tocotrienols.
α-tocopheryl acetate is often used in supplements.
A potent antioxidant.
Protects cell membranes from oxidative stress by donating electrons to oxidizing agents such as reactive oxygen species (ROS).
Deficiency is rare and causes neurological damage.

Fat-Soluble: Vitamin K

Two vitamers: phylloquinone (K₁) and menaquinones (MKs).
Essential for blood clotting and calcium metabolism.
Obtained from gut microflora, such as Escherichia coli, which then release K₁ into the digestive system.
Also found in green leaves and leafy vegetables.
Deficiency in Vitamin K leads to blood clotting issues.

Water-Soluble: Vitamin C

Two vitamers: L-ascorbic acid (L-ascorbate) and dehydroascorbic acid (dehydroascorbate).
An antioxidant protecting cell membranes from damage.
A cofactor for hydroxylases involved in collagen synthesis.
May help prevent scurvy.
Rosehips, blackcurrants, kale, and citrus fruits are good vegetable sources of ascorbic acid.

Hypovitaminosis C

Scurvy is the overarching condition with other symptoms such as bleeding gums, generalized muscle pains, fatigue, anemia from low erythrocyte production, easy bruising, wounds not healing, neuropathy, jaundice, dry eyes, dry mouth, dental caries, mouth ulcers, personality changes, and edema.

Water-Soluble: Thiamine (B₁)

A cofactor for various enzymes, particularly those in the pyruvate dehydrogenase complex.
Essential for many microorganisms.
Beri-beri is characterized by various neuro symptoms.

Water-Soluble: Riboflavin (B₂)

Enzyme cofactors (flavins, e.g. FMN and FAD).
Essential for many microorganisms.
Ariboflavinosis is hypovitaminosis B₂.
Obtained from milk, eggs, meat, green vegetables, and legumes.

Water-Soluble: Niacin (B₃)

Enzyme cofactors (NAD+ and NADP+).
Essential for many microorganisms.
Pellagra is characterized by neuro symptoms, skin rashes, and deficiency.
Obtained from meat, red fishes, grains.

Water-Soluble: Pantothenic Acid (B₅)

Provitamin: panthenol.
Enzyme cofactor coenzyme A (CoA).
Essential for many microorganisms.
Deficiency is very rare.
Obtained from milk, eggs, potatoes, tomatoes, and oats.

Water-Soluble: Pyridoxal 5'-Phosphate (B₆)

Enzyme cofactor itself in many enzymes.
Vitamers include pyridoxine (PN), pyridoxal (PL), PL 5-phosphate, PN 5-phosphate, and pyridoxamine (PM).
Essential for many microorganisms.
Deficiency leads to skin and neurological issues.
Obtained from meat, red fishes, grains.

Water-Soluble: Biotin (B₇)

Enzyme cofactor in many carboxylases.
Essential for many microorganisms.
Regulates gene expression (in some ways).
Deficiency leads to rashes and hallucinations (in various ways).
Obtained from meat, eggs, yeast, and legumes.

Water-Soluble: Folic Acid/Folate (B₉)

Involved in DNA biosynthesis.
Essential for many microorganisms.
Deficiency causes anaemia and impaired neural tube development in pregnancy.
Sources include seeds, legumes, grains, green leafy vegetables.

Water-Soluble: p-Aminobenzoic Acid (B₁₀)

Key for folate synthesis in various microorganisms.
Essential for many microorganisms.
Deficiency is very rare.

Water-Soluble: Cobalamins (B₁₂)

Involved in amino acid and fatty acid biosynthesis. cofactor in methyltransferases/isomerases.
Vitamers include hydroxycobalamin, adenosylcobalamin (adoB₁₂), and methylcobalamin (MeB₁₂).
Essential for many microorganisms.
Deficiency causes anemia, fatigue, joint pain, reduced heart function, depression and psychosis.
Obtained from meat and fish (and other animal sources) where synthesized by microorganisms.

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Description

Test your knowledge on fat-soluble and water-soluble vitamins, provitamins, and the effects of hypovitaminosis. This quiz covers key concepts related to vitamins, their classifications, and daily intake recommendations. Perfect for students and enthusiasts of nutrition science.