1: What essential micro-nutrient is responsible for modifying proteins needed for blood coagulation and calcium binding?
A: Vitamin A
B: Vitamin C
C: Vitamin K
D: Vitamin E
Correct Answer: C
Explanation: Vitamin K is crucial for the post-synthesis modification of proteins, which are necessary for blood coagulation and calcium binding.
2: What enzyme uses Vitamin K as a cofactor for modifying proteins?
A: Gamma-amylase
B: Gamma-glutamyl carboxylase
C: Alpha-glycosidase
D: Beta-lactamase
Correct Answer: B
Explanation: Gamma-glutamyl carboxylase utilizes Vitamin K to modify proteins, specifically for blood coagulation and calcium binding.
3: Which natural vitamer of Vitamin K is directly involved in photosynthesis and found in green leafy vegetables?
A: Vitamin K1
B: Vitamin K2
C: Vitamin K3
D: Vitamin K7
Correct Answer: A
Explanation: Vitamin K1 (phylloquinone) is found in green leafy vegetables and is active in photosynthesis.
4: Which form of Vitamin K is found in higher quantities in fermented foods like natto?
A: Vitamin K1
B: Vitamin K2 MK-7
C: Vitamin K3
D: Vitamin K4
Correct Answer: B
Explanation: Vitamin K2 as MK-7 is abundant in fermented foods such as natto, made by bacteria-fermented soybeans.
5: What primary physiological process would be seriously impaired by Vitamin K deficiency?
A: Protein synthesis
B: Blood coagulation
C: Digestion
D: Respiratory exchange
Correct Answer: B
Explanation: Vitamin K deficiency leads to impaired blood coagulation and can cause uncontrolled bleeding.
6: What indication might suggest a deficiency in Vitamin K?
A: Increased glucose levels
B: Increased cholesterol levels
C: Presence of uncarboxylated proteins
D: Elevated blood pressure
Correct Answer: C
Explanation: The presence of uncarboxylated proteins indicates Vitamin K deficiency since Vitamin K is required for protein carboxylation.
7: Which form of Vitamin K is synthesized by gut bacteria?
A: Vitamin K1
B: Vitamin K2
C: Vitamin K3
D: Vitamin K4
Correct Answer: B
Explanation: Gut bacteria can convert Vitamin K1 to different forms of Vitamin K2, primarily used in the body.
8: Why is Vitamin K1 not used in human nutrition anymore?
A: It interferes with glutathione function
B: It’s too expensive
C: Causes severe allergic reactions
D: It has no known health benefits
Correct Answer: A
Explanation: Vitamin K1 (often referred to as menadione) is no longer used in human nutrition because it interferes with glutathione function.
9: What does “Gla” stand for in the context of Vitamin K-dependent proteins?
A: Gamma-linolenic acid
B: Gamma-carboxyglutamate
C: Glucose-like acetone
D: Gingko lactone acid
Correct Answer: B
Explanation: “Gla” stands for gamma-carboxyglutamate, a modified form of glutamate involved in calcium binding and dependent on Vitamin K.
10: What is the recommended adequate intake of Vitamin K for adult men according to the US National Academy of Medicine?
A: 90 micrograms/day
B: 100 micrograms/day
C: 110 micrograms/day
D: 120 micrograms/day
Correct Answer: D
Explanation: The US National Academy of Medicine recommends an adequate intake of 120 μg/day for adult men.
11: Which country’s dietary guidelines recommend a Vitamin K intake of 75 μg/day for adult men?
A: United States
B: Japan
C: Canada
D: Australia
Correct Answer: B
Explanation: Japan set adequate intake for adult men at 75 μg/day, different from other countries like the US.
12: For what purpose does the US require Vitamin K levels in food to be labeled?
A: To monitor fat content
B: To ensure adequate daily intake
C: To monitor sugar levels
D: To balance iron levels
Correct Answer: B
Explanation: Vitamin K levels in food are labeled in the US to ensure adequate daily intake, which helps in compliance with updated dietary guidelines.
13: Why does the World Health Organization not recommend Vitamin K fortification in foods?
A: There’s no deficiency of Vitamin K
B: It’s too costly
C: It may cause toxicity
D: It’s unstable in foods
Correct Answer: A
Explanation: The WHO does not recommend Vitamin K fortification because Vitamin K deficiency is so rare in the general population.
14: Which food is a rich source of Vitamin K2 MK-7?
A: Spinach
B: Kale
C: Natto (fermented soybeans)
D: Beef
Correct Answer: C
Explanation: Natto, made from fermented soybeans, is an excellent source of Vitamin K2 MK-7 due to bacterial fermentation.
15: Which condition in infants is prevented by Vitamin K injections shortly after birth?
A: Scurvy
B: Vitamin K deficiency bleeding
C: Rickets
D: Limited growth
Correct Answer: B
Explanation: Newborns are given Vitamin K injections to prevent Vitamin K deficiency bleeding, which can lead to severe hemorrhaging.
16: Why is managing Vitamin K intake critical for patients on warfarin therapy?
A: Warfarin increases vitamin absorption
B: Vitamin K stabilizes drug levels
C: Warfarin inhibits Vitamin K recycling
D: Vitamin K is irrelevant to warfarin
Correct Answer: C
Explanation: Warfarin inhibits the enzyme responsible for recycling Vitamin K, necessitating careful monitoring of Vitamin K intake to maintain therapeutic levels.
17: Which dietary feature must people on warfarin therapy regulate?
A: Fat intake
B: Vitamin K intake
C: Carbohydrate intake
D: Sodium intake
Correct Answer: B
Explanation: Patients on warfarin therapy must regulate their Vitamin K intake since it affects warfarin’s efficacy.
18: What vitamin form is primarily obtained from green leafy vegetables?
A: Vitamin K1
B: Vitamin K2
C: Vitamin K3
D: Vitamin K4
Correct Answer: A
Explanation: Green leafy vegetables are rich in Vitamin K1 (phylloquinone).
19: Which marker is most commonly used to assess Vitamin K status?
A: Serum calcium levels
B: Serum phylloquinone
C: Serum potassium levels
D: Serum magnesium levels
Correct Answer: B
Explanation: Serum phylloquinone is typically used to gauge Vitamin K status, with levels <0.15 μg/L indicating deficiency.
20: What can untreated Vitamin K deficiency lead to in severe cases?
A: Reduced blood clotting
B: Increased skin elasticity
C: Enhanced muscle strength
D: Improved vision
Correct Answer: A
Explanation: Severe Vitamin K deficiency can cause reduced blood clotting, resulting in increased bleeding.
21: What are the two most studied subtypes of Vitamin K2?
A: K1 and K4
B: K3 and K5
C: MK-4 and MK-7
D: K2 and K6
Correct Answer: C
Explanation: MK-4 and MK-7 are the two most studied subtypes of Vitamin K2, with differing side chain lengths and functions.
22: What is the primary source of dietary Vitamin K1?
A: Animal-sourced foods
B: Green leafy vegetables
C: Processed foods
D: Dairy products
Correct Answer: B
Explanation: The primary dietary source of Vitamin K1 is green leafy vegetables like spinach, kale, and collard greens.
23: Which organ primarily uses Vitamin K for synthesizing blood clotting proteins?
A: Heart
B: Liver
C: Kidneys
D: Lungs
Correct Answer: B
Explanation: The liver uses Vitamin K to synthesize essential blood clotting proteins.
24: Which form of Vitamin K is produced synthetically and no longer used due to its side effects?
A: K1
B: K2
C: K3 (menadione)
D: MK-4
Correct Answer: C
Explanation: Vitamin K3 (menadione) is no longer used in human nutrition due to its interference with glutathione function.
25: Which enzyme helps recycle Vitamin K to a functional state, which is inhibited by warfarin?
A: Vitamin K epoxide reductase (VKOR)
B: Lipase
C: Amylase
D: Catalase
Correct Answer: A
Explanation: Vitamin K epoxide reductase (VKOR) is responsible for recycling Vitamin K, inhibition of which is the target of the drug warfarin.
26: How much Vitamin K is recommended for pregnant and lactating women by the US National Academy of Medicine?
A: 90 μg/day
B: 120 μg/day
C: 100 μg/day
D: 80 μg/day
Correct Answer: A
Explanation: For pregnant and lactating women, the recommended adequate intake of Vitamin K is 90 μg/day.
27: What is the major side effect reported for intravenous administration of Vitamin K1?
A: Severe allergic reactions
B: Enhanced energy levels
C: Digestive issues
D: Heart palpitations
Correct Answer: A
Explanation: Intravenous Vitamin K1 administration can lead to severe allergic reactions, specifically nonimmune-mediated anaphylactoid reactions.
28: What animal food source provides the most Vitamin K2?
A: Chicken
B: Beef
C: Goose
D: Salmon
Correct Answer: C
Explanation: Goose meat is among the richest animal sources of Vitamin K2.
29: Which type of research method was initially used to quantify Vitamin K in foods before modern assays?
A: Blood serum analysis
B: Chick feeding model
C: Human clinical trials
D: Mass spectrometry
Correct Answer: B
Explanation: Quantifying Vitamin K levels in foods historically involved feeding vitamin K–deficient chicks and observing the restoration of blood coagulation.
30: What compound in Vitamin K’s structure allows it to function biologically relevantly?
A: 2-methyl-1,4-naphthoquinone
B: 3-methylflavanone
C: 6-ketomethylphthalate
D: 9-anthracene
Correct Answer: A
Explanation: The chemical structure of Vitamin K includes 2-methyl-1,4-naphthoquinone, which allows its biological activity.
31: According to the European Union, what is the recommended adequate intake of Vitamin K for lactating women?
A: 90 μg/day
B: 70 μg/day
C: 100 μg/day
D: 50 μg/day
Correct Answer: B
Explanation: For lactating women, the recommended adequate intake of Vitamin K by the European Union is set at 70 μg/day.
32: In which type of cells does the conversion of Vitamin K1 to Vitamin K2 MK-4 occur in animals?
A: Liver cells
B: Testes cells
C: Muscle cells
D: Skin cells
Correct Answer: B
Explanation: The conversion of Vitamin K1 to Vitamin K2 MK-4 in animals occurs primarily in the testes, pancreas, and arterial walls.
33: What regulatory agency has banned menadione (Vitamin K3) from sale as a human dietary supplement?
A: Food and Drug Administration (FDA)
B: Centers for Disease Control and Prevention (CDC)
C: Environmental Protection Agency (EPA)
D: National Institutes of Health (NIH)
Correct Answer: A
Explanation: The US Food and Drug Administration (FDA) has banned the use of menadione as a human dietary supplement due to its adverse effects.
34: Which protein mutation might be measured to assess the risk of Vitamin K-deficient bleeding in newborns?
A: PIVKA-II (Protein Induced by Vitamin K Absence)
B: CRP (C-Reactive Protein)
C: Hemoglobin
D: Albumin
Correct Answer: A
Explanation: PIVKA-II is a marker measured to assess the risk of Vitamin K-deficient bleeding in newborns.
35: What enzyme converts Vitamin K hydroquinone to allow carboxylation of proteins?
A: Vitamin K epoxide reductase (VKOR)
B: Gamma-glutamyl carboxylase
C: Alpha-butyryl coenzyme
D: Delta-aminolevulinic acid
Correct Answer: B
Explanation: Gamma-glutamyl carboxylase converts Vitamin K hydroquinone, facilitating the carboxylation of Glu residues on proteins.
36: Which bacterial species in the large intestine synthesize Vitamin K2?
A: Lactobacillus
B: Escherichia coli
C: Staphylococcus aureus
D: Streptococcus pneumoniae
Correct Answer: B
Explanation: E. coli and many other bacteria in the large intestine can synthesize Vitamin K2.
37: What adverse effect is associated with injectable Vitamin K1 that uses polyoxyethylated castor oil as the solubilizing agent?
A: Bronchospasm
B: Diarrhea
C: Headache
D: Insomnia
Correct Answer: A
Explanation: Injectable Vitamin K1 using polyoxyethylated castor oil as a solubilizing agent can cause severe adverse reactions such as bronchospasm.
38: Which vitamin is chemically similar to Vitamin K but banned in the pet food industry for causing toxicity at high doses?
A: Vitamin K1
B: Vitamin K2
C: Vitamin K3
D: Vitamin K4
Correct Answer: C
Explanation: Menadione, often referred to as Vitamin K3, is banned due to its potential toxicity, causing reactions like hemolytic anemia.
39: What biological role does Vitamin K play in plants?
A: Photosynthesis
B: Nitrogen fixation
C: Seed germination
D: Water transport
Correct Answer: A
Explanation: In plants, especially green foliage, Vitamin K1 plays a crucial role in photosynthesis.
40: What function does Vitamin K2 serve in bacterial anaerobic respiration?
A: It acts as an electron donor
B: It is an electron acceptor
C: It serves as an energy source
D: It converts to oxygen
Correct Answer: B
Explanation: In bacteria, Vitamin K2 acts as an electron acceptor during anaerobic respiration.
41: In what year did the US National Academy of Medicine last update the dietary recommendations for Vitamin K?
A: 2016
B: 2019
C: 1998
D: 2005
Correct Answer: C
Explanation: The last update for dietary recommendations for Vitamin K by the US National Academy of Medicine was in 1998.
42: What primary reaction is associated with anaphylactoid responses seen in Vitamin K1 injections?
A: Increased blood pressure
B: Immune-mediated reactions
C: Nonimmune-mediated reactions
D: Decreased heart rate
Correct Answer: C
Explanation: Anaphylactoid reactions observed with intravenous Vitamin K1 are nonimmune-mediated.
43: Why was the Nobel Prize awarded in 1943 to Henrik Dam and Edward Adelbert Doisy?
A: Discovery of insulin
B: Discovery of Vitamin C
C: Discovery and research on Vitamin K1 and K2
D: Discovery of antibiotics
Correct Answer: C
Explanation: Henrik Dam and Edward Adelbert Doisy received the Nobel Prize in 1943 for their work on Vitamin K1 and K2.
44: Which vegetable holds the highest amount of Vitamin K1 as per the chart provided?
A: Spinach (raw, 1 cup)
B: Collard greens (boiled, ½ cup)
C: Broccoli (boiled, ½ cup)
D: Asparagus (boiled, 4 spears)
Correct Answer: B
Explanation: Boiled collard greens provide the highest amount of Vitamin K1 as per the dietary source list.
45: Which of the following is NOT a role of Vitamin K in the body?
A: Blood coagulation
B: Bone metabolism
C: Vascular biology
D: Muscle synthesis
Correct Answer: D
Explanation: While Vitamin K is vital for blood coagulation, bone metabolism, and vascular biology, it is not directly related to muscle synthesis.
46: What biochemical pathway is NOT influenced by Vitamin K?
A: Liver’s synthesis of clotting factors
B: Gut flora’s synthesis of Vitamin K2
C: Photosynthesis in plants
D: Oxygen transport in blood
Correct Answer: D
Explanation: Vitamin K does not play a role in blood oxygen transport.
47: Which vitamin K-dependent protein assists with inhibiting vascular calcification?
A: Osteocalcin
B: Protein S
C: Matrix Gla protein (MGP)
D: Prothrombin
Correct Answer: C
Explanation: Matrix Gla protein (MGP) helps inhibit vascular calcification.
48: Which drug is known to inhibit Vitamin K absorption, potentiating the effect of warfarin?
A: Ezetimibe
B: Ibuprofen
C: Metformin
D: Amoxicillin
Correct Answer: A
Explanation: Ezetimibe inhibits NPC1L1, reducing Vitamin K absorption, thus potentiating the warfarin effect.
49: What is the role of gamma-carboxyglutamate residues in proteins?
A: Protein folding
B: Binding calcium ions
C: Increasing solubility
D: Enhancing color
Correct Answer: B
Explanation: Gamma-carboxyglutamate residues in proteins are crucial for binding calcium ions, often central to their function.
50: Which blood clotting factor is Vitamin K-dependent and crucial for its biological activity?
A: Fibrinogen
B: Factor VII
C: Hemoglobin
D: Myoglobin
Correct Answer: B
Explanation: Factor VII is one of the critical blood clotting factors dependent on Vitamin K for its biological activity.
51: What is the primary method of assessing Vitamin K status in newborns?
A: Serum cholesterol levels
B: Serum osteocalcin ratio
C: Assays measuring uncarboxylated proteins
D: Blood glucose levels
Correct Answer: C
Explanation: Measuring the levels of uncarboxylated proteins is a specific marker for assessing Vitamin K status in newborns.
52: Which green leafy vegetable typically has the highest Vitamin K content per cup when raw?
A: Spinach
B: Kale
C: Broccoli
D: Collard greens
Correct Answer: A
Explanation: Among common leafy vegetables, spinach, when consumed raw, typically offers the most Vitamin K content per cup.
53: Which form of Vitamin K is synthesized and given to infants to prevent Vitamin K deficiency?
A: Vitamin K2
B: Vitamin K3
C: Vitamin K1
D: Vitamin K4
Correct Answer: C
Explanation: Vitamin K1 is synthesized and administered to newborn infants to prevent Vitamin K deficiency.
54: Which is not a recognized form of Vitamin K?
A: K1
B: K2
C: MK-7
D: K4
Correct Answer: D
Explanation: While K1, K2, and MK-7 are recognized forms of Vitamin K, there is no form officially designated as K4.
55: What adverse condition is associated with deficiency of Vitamin K in newborns?
A: Osteoporosis
B: Vitamin K deficiency bleeding
C: Scurvy
D: Anemia
Correct Answer: B
Explanation: Vitamin K deficiency in newborns can lead to Vitamin K deficiency bleeding, which is characterized by severe bleeding that can result in fatal consequences.
56: Which of these foods provides the lowest amount of Vitamin K1 per serving?
A: Chicken, 113g (4 oz)
B: Mollusks, 113g (4 oz)
C: Fish, 113g (4 oz)
D: Eggs, one
Correct Answer: C
Explanation: Among the listed choices, fish (113g) generally contains the lowest amount of Vitamin K1.
57: What happens to the blood coagulation process without sufficient Vitamin K?
A: It speeds up
B: It becomes more regulated
C: It is seriously impaired
D: It has no effect
Correct Answer: C
Explanation: Without sufficient Vitamin K, the blood coagulation process is severely impaired, which can lead to uncontrolled bleeding.
58: How frequently should oral Vitamin K be administered to prevent bleeding in newborns if intramuscular injection is not used?
A: Monthly
B: Every other week
C: Weekly up to three months
D: Daily up to one month
Correct Answer: C
Explanation: If intramuscular injection is not used, oral Vitamin K should be administered weekly up to three months of age to prevent bleeding in newborns.
59: What is the primary absorption site for Vitamin K in the human body?
A: Jejunum and ileum
B: Stomach
C: Duodenum
D: Large intestine
Correct Answer: A
Explanation: Vitamin K is primarily absorbed in the jejunum and ileum sections of the small intestine.
60: In what year was the effective terminal end date for compliance with updated Vitamin K labeling regulations for manufacturers with lower volume food sales?
A: January 1, 2020
B: January 1, 2021
C: January 1, 2019
D: January 1, 2022
Correct Answer: B
Explanation: Manufacturers with lower volume food sales were required to comply with the updated Vitamin K labeling regulations by January 1, 2021.
Disclaimer: Please consult a physician before making any changes to your health regimen.