Calcium
Q1.
Which of the following hormones increases blood calcium levels?
A. Calcitonin
B. Insulin
C. Parathyroid hormone (PTH)
D. Glucagon
Q2.
The normal serum calcium level in adults ranges approximately between:
A. 2–3 mg/dL
B. 4–6 mg/dL
C. 8.5–10.5 mg/dL
D. 12–15 mg/dL
Q3.
Which of the following vitamins is essential for intestinal absorption of calcium?
A. Vitamin A
B. Vitamin B12
C. Vitamin D
D. Vitamin K
Q4.
Tetany in hypocalcemia occurs due to:
A. Increased muscle mass
B. Decreased neuromuscular excitability
C. Increased neuromuscular excitability
D. Increased bone formation
Q5.
Which form of calcium in plasma is biologically active?
A. Protein-bound calcium
B. Ionized (free) calcium
C. Calcium-phosphate complex
D. Calcium-citrate complex
Q6.
Which of the following conditions is least likely to cause hypocalcemia?
A. Vitamin D deficiency
B. Hypoparathyroidism
C. Renal failure
D. Hyperparathyroidism
Q7.
Which of the following statements about calcium is incorrect?
A. 99% of body calcium is stored in bones and teeth
B. Calcium is required for blood coagulation
C. Calcium inhibits muscle contraction
D. Calcium plays a role in nerve impulse transmission
Q8.
Chvostek’s and Trousseau’s signs are clinical features of:
A. Hypercalcemia
B. Hypocalcemia
C. Hyperkalemia
D. Hypokalemia
Q9.
Calcium absorption from the intestine is enhanced by:
A. High dietary phosphate
B. Alkaline pH in the intestine
C. Phytic acid in the diet
D. Vitamin D
Q10.
Which of the following is not a function of calcium?
A. Muscle contraction
B. Activation of some enzymes
C. DNA synthesis
D. Blood clotting
✅ Answer Key –
-
C. Parathyroid hormone (PTH)
-
C. 8.5–10.5 mg/dL
-
C. Vitamin D
-
C. Increased neuromuscular excitability
-
B. Ionized (free) calcium
-
D. Hyperparathyroidism
-
C. Calcium inhibits muscle contraction
-
B. Hypocalcemia
-
D. Vitamin D
-
C. DNA synthesis
Phosphorus
Q1.
Which of the following is the major storage site of phosphorus in the human body?
A. Liver
B. Muscle
C. Bones and teeth
D. Kidneys
Q2.
The major form of phosphorus in plasma is:
A. Organic phosphate
B. Inorganic phosphate
C. Phospholipids
D. Phosphate esters
Q3.
Phosphorus plays an important role in all of the following except:
A. Energy metabolism
B. DNA and RNA structure
C. Hemoglobin synthesis
D. Bone mineralization
Q4.
Which hormone increases the renal excretion of phosphate?
A. Insulin
B. Parathyroid hormone (PTH)
C. Calcitonin
D. Aldosterone
Q5.
Which of the following is not a dietary source of phosphorus?
A. Milk
B. Eggs
C. Fruits
D. Meat
Q6.
The active form of vitamin D that helps in phosphate absorption is:
A. Cholecalciferol
B. 25-hydroxycholecalciferol
C. 1,25-dihydroxycholecalciferol
D. Ergocalciferol
Q7.
Hypophosphatemia is least likely to occur in:
A. Vitamin D deficiency
B. Hyperparathyroidism
C. Chronic alcoholism
D. Hypoparathyroidism
Q8.
Which enzyme involved in energy metabolism requires phosphate?
A. Hexokinase
B. DNA polymerase
C. Amylase
D. Catalase
Q9.
Which of the following is a clinical manifestation of hypophosphatemia?
A. Tetany
B. Osteomalacia
C. Hyperreflexia
D. Hypertension
Q10.
Hyperphosphatemia is commonly seen in:
A. Rickets
B. Chronic kidney disease
C. Hyperparathyroidism
D. Vitamin D deficiency
✅ Answer Key –
-
C. Bones and teeth
-
B. Inorganic phosphate
-
C. Hemoglobin synthesis
-
B. Parathyroid hormone (PTH)
-
C. Fruits
-
C. 1,25-dihydroxycholecalciferol
-
D. Hypoparathyroidism
-
A. Hexokinase
-
B. Osteomalacia
-
B. Chronic kidney disease
Magnesium
Q1.
Which of the following is the major intracellular divalent cation?
A. Calcium
B. Sodium
C. Potassium
D. Magnesium
Q2.
Magnesium acts as a cofactor in which of the following processes?
A. Lipid transport
B. DNA replication
C. Oxidative deamination
D. Oxygen transport
Q3.
A deficiency of magnesium may cause:
A. Tetany and muscle cramps
B. Night blindness
C. Megaloblastic anemia
D. Hyperpigmentation
Q4.
Which of the following enhances magnesium absorption?
A. High calcium intake
B. High fiber diet
C. Active vitamin D (calcitriol)
D. Low pH in intestine
Q5.
Major storage site of magnesium in the body is:
A. Blood plasma
B. Muscles
C. Liver
D. Bones
Chlorine (Chloride)
Q6.
Chloride is mainly present in:
A. Intracellular fluid
B. Plasma proteins
C. Extracellular fluid
D. Red blood cells
Q7.
Which of the following functions is not related to chloride?
A. Maintenance of osmotic pressure
B. Formation of HCl in stomach
C. Nerve impulse conduction
D. Oxygen transport
Q8.
Hypochloremia may be seen in which condition?
A. Dehydration
B. Vomiting
C. Hyperkalemia
D. Addison’s disease
Q9.
Chloride shift in red blood cells is important for:
A. Protein synthesis
B. Carbon dioxide transport
C. Oxygen binding
D. Glucose metabolism
Q10.
Which hormone indirectly regulates chloride balance via sodium handling?
A. Calcitonin
B. Parathyroid hormone
C. Aldosterone
D. Vasopressin
Sulphur
Q11.
Sulphur is a component of which of the following amino acids?
A. Valine and leucine
B. Methionine and cysteine
C. Phenylalanine and tyrosine
D. Lysine and arginine
Q12.
Sulphur is involved in the detoxification process in the liver via:
A. Methylation
B. Phosphorylation
C. Sulphation
D. Hydroxylation
Q13.
Biotin and thiamine are examples of:
A. Iron-containing vitamins
B. Zinc-dependent vitamins
C. Sulphur-containing vitamins
D. Calcium-binding vitamins
Q14.
The inorganic form of sulphur is excreted from the body mainly as:
A. Sulphate
B. Sulfite
C. Methionine
D. Sulfur dioxide
Q15.
Which of the following enzymes requires a sulphur-containing amino acid at its active site?
A. Hexokinase
B. Glutathione peroxidase
C. Sucrase
D. DNA polymerase
✅ Answer Key – Magnesium, Chlorine & Sulphur
| Q.No | Answer |
|---|---|
| 1 | D. Magnesium |
| 2 | B. DNA replication |
| 3 | A. Tetany and muscle cramps |
| 4 | C. Active vitamin D (calcitriol) |
| 5 | D. Bones |
| 6 | C. Extracellular fluid |
| 7 | D. Oxygen transport |
| 8 | B. Vomiting |
| 9 | B. Carbon dioxide transport |
| 10 | C. Aldosterone |
| 11 | B. Methionine and cysteine |
| 12 | C. Sulphation |
| 13 | C. Sulphur-containing vitamins |
| 14 | A. Sulphate |
| 15 | B. Glutathione peroxidase |
Iron
Q1.
The major site of iron absorption in the gastrointestinal tract is:
A. Stomach
B. Duodenum
C. Jejunum
D. Ileum
Q2.
Which form of dietary iron is better absorbed?
A. Ferric (Fe³⁺)
B. Ferrous (Fe²⁺)
C. Elemental iron
D. Heme-free iron
Q3.
The iron storage form in tissues is:
A. Transferrin
B. Ferritin
C. Hemosiderin
D. Hemoglobin
Q4.
Which of the following enhances iron absorption?
A. Phytates
B. Calcium
C. Vitamin C
D. Oxalates
Q5.
Which protein transports iron in the blood?
A. Ferritin
B. Myoglobin
C. Transferrin
D. Ceruloplasmin
Q6.
Iron is primarily excreted from the body via:
A. Urine
B. Sweat
C. Feces
D. Bile
Q7.
Which of the following is a symptom of iron-deficiency anemia?
A. Jaundice
B. Koilonychia (spoon nails)
C. Cyanosis
D. Weight gain
Q8.
The daily dietary requirement of iron for adult females is approximately:
A. 1 mg
B. 5 mg
C. 10–12 mg
D. 18–20 mg
Q9.
Iron is an essential component of:
A. Amylase
B. Myoglobin
C. Collagen
D. Keratin
Q10.
Which enzyme involved in iron metabolism converts Fe²⁺ to Fe³⁺?
A. Ferrochelatase
B. Transaminase
C. Cytochrome oxidase
D. Ceruloplasmin
Sodium & Potassium
Q11.
Sodium is primarily found in:
A. Intracellular fluid
B. Plasma proteins
C. Extracellular fluid
D. Mitochondria
Q12.
Potassium is essential for:
A. Protein digestion
B. Neuromuscular excitability
C. Bile secretion
D. Blood clotting
Q13.
Aldosterone increases the reabsorption of:
A. Potassium
B. Sodium
C. Calcium
D. Phosphate
Q14.
Hypokalemia is associated with:
A. Diarrhea
B. Bradycardia
C. Hypotension
D. Tetany
Q15.
Which of the following is a clinical sign of hyperkalemia?
A. Flattened T wave
B. Prolonged QT interval
C. Peaked T wave
D. Short PR interval
Q16.
Sodium-potassium ATPase pump transports:
A. 3 Na⁺ in, 2 K⁺ out
B. 3 K⁺ in, 2 Na⁺ out
C. 3 Na⁺ out, 2 K⁺ in
D. Equal Na⁺ and K⁺ exchange
Q17.
Which hormone helps regulate sodium and water balance?
A. Cortisol
B. Insulin
C. Antidiuretic hormone (ADH)
D. Epinephrine
Q18.
The most common cause of hyponatremia is:
A. Renal failure
B. Vomiting
C. Diuretic use
D. Excess water intake
Q19.
Potassium is mainly excreted through:
A. Skin
B. Lungs
C. Liver
D. Kidneys
Q20.
The normal serum potassium level is:
A. 2–3 mmol/L
B. 3.5–5.0 mmol/L
C. 5.5–7.0 mmol/L
D. 1–2 mmol/L
✅ Answer Key
Iron:
| Q | Ans |
|---|---|
| 1 | B. Duodenum |
| 2 | B. Ferrous (Fe²⁺) |
| 3 | B. Ferritin |
| 4 | C. Vitamin C |
| 5 | C. Transferrin |
| 6 | C. Feces |
| 7 | B. Koilonychia (spoon nails) |
| 8 | D. 18–20 mg |
| 9 | B. Myoglobin |
| 10 | D. Ceruloplasmin |
Sodium & Potassium:
| Q | Ans |
|---|---|
| 11 | C. Extracellular fluid |
| 12 | B. Neuromuscular excitability |
| 13 | B. Sodium |
| 14 | A. Diarrhea |
| 15 | C. Peaked T wave |
| 16 | C. 3 Na⁺ out, 2 K⁺ in |
| 17 | C. Antidiuretic hormone (ADH) |
| 18 | D. Excess water intake |
| 19 | D. Kidneys |
| 20 | B. 3.5–5.0 mmol/L |
Copper
Q1.
Copper is mainly absorbed in the:
A. Stomach
B. Duodenum
C. Jejunum
D. Ileum
Q2.
Which protein is responsible for copper transport in the blood?
A. Ceruloplasmin
B. Transferrin
C. Ferritin
D. Albumin
Q3.
Copper is a cofactor for which enzyme involved in connective tissue formation?
A. Cytochrome c oxidase
B. Lysyl oxidase
C. Catalase
D. Alkaline phosphatase
Q4.
Wilson’s disease is characterized by:
A. Iron overload
B. Copper accumulation
C. Zinc deficiency
D. Manganese excess
Q5.
Which of the following is a clinical feature of Wilson’s disease?
A. Kayser-Fleischer rings
B. Cherry red spot on macula
C. Blue sclera
D. Peripheral neuropathy
Q6.
Excess copper toxicity primarily affects the:
A. Heart and lungs
B. Liver and brain
C. Kidneys and pancreas
D. Skin and bones
Q7.
Copper deficiency can cause:
A. Megaloblastic anemia
B. Neutropenia and bone abnormalities
C. Hemolytic anemia
D. Polycythemia
Q8.
Copper acts as a cofactor in which of the following oxidative enzymes?
A. Glucose-6-phosphatase
B. Superoxide dismutase (SOD)
C. Lactate dehydrogenase
D. DNA polymerase
Q9.
Which dietary factor decreases copper absorption?
A. Vitamin C
B. Phytates
C. Heme iron
D. Vitamin D
Q10.
The major route of copper excretion is through:
A. Urine
B. Bile
C. Sweat
D. Feces
Iodine
Q11.
Iodine is primarily absorbed in the:
A. Stomach
B. Duodenum
C. Jejunum
D. Ileum
Q12.
Iodine is essential for synthesis of:
A. Insulin
B. Thyroid hormones
C. Parathyroid hormone
D. Adrenal hormones
Q13.
Which form of iodine is actively transported into the thyroid gland?
A. Iodide (I⁻)
B. Iodate (IO₃⁻)
C. Elemental iodine (I₂)
D. Organic iodine compounds
Q14.
Deficiency of iodine in the diet leads to:
A. Cretinism and goiter
B. Anemia
C. Osteoporosis
D. Diabetes mellitus
Q15.
Which hormone stimulates iodine uptake by the thyroid gland?
A. TSH (Thyroid-stimulating hormone)
B. ACTH
C. Growth hormone
D. Parathyroid hormone
Q16.
The Wolff-Chaikoff effect is:
A. Stimulation of thyroid hormone synthesis by iodine
B. Inhibition of thyroid hormone synthesis due to excess iodine
C. Autoimmune destruction of thyroid gland
D. Increased iodine excretion by kidneys
Q17.
Iodine is stored in the thyroid gland mainly as:
A. Free iodide ions
B. Thyroglobulin-bound iodide
C. Iodate salts
D. Organic iodine in blood
Q18.
Which of the following is a common clinical sign of iodine deficiency in children?
A. Macroglossia
B. Goiter
C. Café-au-lait spots
D. Night blindness
Q19.
Excess iodine intake can cause:
A. Hypothyroidism
B. Hyperthyroidism
C. Both A and B
D. No effect on thyroid
Q20.
Which of the following is used to prevent iodine deficiency disorders?
A. Fluoridation of water
B. Iodization of salt
C. Vitamin A supplementation
D. Iron fortification
✅ Answer Key
| Q.No | Answer |
|---|---|
| 1 | B. Duodenum |
| 2 | A. Ceruloplasmin |
| 3 | B. Lysyl oxidase |
| 4 | B. Copper accumulation |
| 5 | A. Kayser-Fleischer rings |
| 6 | B. Liver and brain |
| 7 | B. Neutropenia and bone abnormalities |
| 8 | B. Superoxide dismutase (SOD) |
| 9 | B. Phytates |
| 10 | B. Bile |
| 11 | B. Duodenum |
| 12 | B. Thyroid hormones |
| 13 | A. Iodide (I⁻) |
| 14 | A. Cretinism and goiter |
| 15 | A. TSH |
| 16 | B. Inhibition of thyroid hormone synthesis due to excess iodine |
| 17 | B. Thyroglobulin-bound iodide |
| 18 | B. Goiter |
| 19 | C. Both A and B |
| 20 | B. Iodization of salt |
Zinc
Q1.
Zinc is primarily absorbed in the:
A. Stomach
B. Duodenum
C. Jejunum
D. Ileum
Q2.
Which protein is the major carrier of zinc in the blood?
A. Transferrin
B. Albumin
C. Ceruloplasmin
D. Ferritin
Q3.
Zinc is an essential cofactor for which of the following enzymes?
A. DNA polymerase
B. Lactase
C. Pepsin
D. Amylase
Q4.
Which of the following is a clinical feature of zinc deficiency?
A. Night blindness
B. Delayed wound healing
C. Goiter
D. Anemia
Q5.
Which food source is rich in zinc?
A. Citrus fruits
B. Meat and seafood
C. Leafy green vegetables
D. Dairy products
Q6.
Zinc plays a crucial role in:
A. Collagen synthesis
B. Taste perception
C. Vitamin D metabolism
D. Insulin secretion
Q7.
Excess intake of zinc may cause:
A. Copper deficiency
B. Iron overload
C. Magnesium toxicity
D. Calcium deficiency
Q8.
Zinc finger proteins are important in:
A. Cell membrane transport
B. DNA binding and gene regulation
C. Mitochondrial respiration
D. Protein digestion
Q9.
Which of the following inhibits zinc absorption?
A. Phytates
B. Vitamin C
C. Calcium
D. Vitamin A
Q10.
Zinc deficiency is most commonly seen in:
A. Alcoholism
B. Hyperthyroidism
C. Chronic kidney disease
D. Diabetes mellitus
✅ Answer Key – Zinc
-
B. Duodenum
-
B. Albumin
-
A. DNA polymerase
-
B. Delayed wound healing
-
B. Meat and seafood
-
B. Taste perception
-
A. Copper deficiency
-
B. DNA binding and gene regulation
-
A. Phytates
-
A. Alcoholism
Fluorine (Fluoride)
Q1.
The primary role of fluoride in the human body is:
A. Enhancing vitamin D absorption
B. Preventing dental caries
C. Enhancing iron absorption
D. Promoting muscle contraction
Q2.
Fluoride is mainly deposited in:
A. Liver and spleen
B. Cartilage and joints
C. Teeth and bones
D. Skin and hair
Q3.
Which of the following is a common source of fluoride?
A. Sea salt
B. Fluoridated drinking water
C. Citrus fruits
D. Milk
Q4.
Excessive intake of fluoride during tooth development may lead to:
A. Dental caries
B. Gingivitis
C. Dental fluorosis
D. Enamel hypoplasia due to calcium deficiency
Q5.
Fluorosis affects which body system most prominently?
A. Nervous system
B. Skeletal system
C. Endocrine system
D. Cardiovascular system
Selenium
Q6.
Selenium is an essential component of which antioxidant enzyme?
A. Catalase
B. Glutathione peroxidase
C. Superoxide dismutase
D. Peroxidase
Q7.
Selenium deficiency is associated with:
A. Rickets
B. Keshan disease
C. Pellagra
D. Wilson’s disease
Q8.
Which of the following is a rich dietary source of selenium?
A. Leafy vegetables
B. Whole grains and nuts (esp. Brazil nuts)
C. Citrus fruits
D. Milk
Q9.
Selenium plays an important role in the metabolism of which hormone?
A. Insulin
B. Thyroxine (T4)
C. Estrogen
D. Cortisol
Q10.
Toxic levels of selenium can lead to:
A. Hypokalemia
B. Liver cirrhosis
C. Garlic odor in breath and hair loss
D. Goiter
✅ Answer Key – Fluorine & Selenium
| Q.No | Answer |
|---|---|
| 1 | B. Preventing dental caries |
| 2 | C. Teeth and bones |
| 3 | B. Fluoridated drinking water |
| 4 | C. Dental fluorosis |
| 5 | B. Skeletal system |
| 6 | B. Glutathione peroxidase |
| 7 | B. Keshan disease |
| 8 | B. Whole grains and nuts (esp. Brazil nuts) |
| 9 | B. Thyroxine (T4) |
| 10 | C. Garlic odor in breath and hair loss |
Case-Based & Analytical MCQs
Q1.
A 30-year-old woman presents with brittle nails, hair loss, and pale conjunctiva. Lab results show microcytic hypochromic anemia and low serum ferritin. Which mineral deficiency is most likely?
A. Iron
B. Zinc
C. Copper
D. Selenium
Q2.
A 2-year-old child from a fluoride-deficient area develops multiple dental caries. Which intervention will most directly address the underlying issue?
A. Calcium supplementation
B. Fluoridated water
C. Vitamin D drops
D. Iron syrup
Q3.
A patient presents with tremors, ataxia, and psychiatric disturbances. Slit-lamp exam shows Kayser-Fleischer rings. What is the most likely biochemical abnormality?
A. Iron accumulation
B. Zinc toxicity
C. Copper accumulation
D. Selenium deficiency
Q4.
A 45-year-old male with chronic diarrhea develops muscle weakness and ECG changes. Labs show low serum potassium. Which of the following is the most immediate risk?
A. Hypercalcemia
B. Cardiac arrhythmia
C. Liver failure
D. Osteomalacia
Q5.
A neonate on prolonged parenteral nutrition presents with poor wound healing and dermatitis. Suspecting a trace mineral deficiency, which is most likely?
A. Iron
B. Magnesium
C. Zinc
D. Fluoride
Q6.
A 10-year-old child presents with bowed legs and delayed growth. Biochemical evaluation reveals low calcium and phosphate with elevated PTH. Which mineral is implicated in the pathogenesis?
A. Iodine
B. Selenium
C. Calcium
D. Iron
Q7.
A 70-year-old woman presents with fractures despite normal calcium levels. Her diet is low in dairy, and she avoids sunlight. Which mineral is most likely contributing to her condition?
A. Magnesium
B. Zinc
C. Phosphorus
D. Vitamin D-dependent calcium absorption
Q8.
In a patient with chronic kidney disease, hyperphosphatemia is observed. What is the most likely physiological cause?
A. Decreased phosphate intake
B. Increased renal reabsorption
C. Decreased phosphate excretion
D. Vitamin D excess
Q9.
A malnourished child presents with hypopigmented hair, growth retardation, and recurrent infections. Which trace mineral deficiency is suspected?
A. Copper
B. Zinc
C. Selenium
D. Fluoride
Q10.
A child with endemic cretinism presents with stunted growth and mental retardation. Which mineral is deficient?
A. Iron
B. Iodine
C. Magnesium
D. Calcium
Q11.
A 55-year-old male presents with visual disturbances and increased oxidative stress markers. Glutathione peroxidase activity is low. Which mineral deficiency is likely?
A. Zinc
B. Iron
C. Selenium
D. Copper
Q12.
An alcoholic patient presents with neuromuscular irritability, tremors, and a positive Chvostek’s sign. Labs show hypocalcemia. Which mineral deficiency is likely contributing?
A. Magnesium
B. Phosphorus
C. Iron
D. Potassium
Q13.
A farmer exposed to excess fluoride in groundwater develops stiff joints and mottled teeth. What is the condition?
A. Dental caries
B. Skeletal fluorosis
C. Rickets
D. Osteomalacia
Q14.
A patient with thyroid swelling is found to have low T3/T4 and high TSH. He lives in a mountainous region with iodine-deficient soil. What is the most appropriate long-term public health measure?
A. Iron fortification
B. Iodized salt distribution
C. Zinc supplementation
D. Selenium drops
Q15.
A patient with nephrotic syndrome develops hypocalcemia. Which protein-bound mineral is lost in urine and contributes to this condition?
A. Zinc
B. Phosphate
C. Iron
D. Calcium
Q16.
A young woman on a crash diet complains of fatigue and palpitations. Her labs show low hemoglobin, low serum iron, and high TIBC. What is the most likely diagnosis?
A. Hemolytic anemia
B. Iron deficiency anemia
C. Megaloblastic anemia
D. Sideroblastic anemia
Q17.
A man presents with arrhythmias and hypotension. ECG shows flattened T-waves. He is on thiazide diuretics. What is the likely electrolyte abnormality?
A. Hypernatremia
B. Hyperkalemia
C. Hypokalemia
D. Hypercalcemia
Q18.
A child with Menkes disease shows neurodegeneration and connective tissue defects. This is due to a defect in absorption of:
A. Zinc
B. Iron
C. Copper
D. Manganese
Q19.
Increased urinary calcium excretion is a hallmark of:
A. Hypoparathyroidism
B. Hyperparathyroidism
C. Iron-deficiency anemia
D. Addison’s disease
Q20.
A patient with hypertension is placed on a low-sodium diet. Which of the following is an expected physiological response?
A. Increased aldosterone secretion
B. Decreased renin
C. Increased sodium excretion
D. Decreased water reabsorption
✅ Answer Key
| Q.No | Answer |
|---|---|
| 1 | A. Iron |
| 2 | B. Fluoridated water |
| 3 | C. Copper accumulation |
| 4 | B. Cardiac arrhythmia |
| 5 | C. Zinc |
| 6 | C. Calcium |
| 7 | D. Vitamin D-dependent calcium absorption |
| 8 | C. Decreased phosphate excretion |
| 9 | B. Zinc |
| 10 | B. Iodine |
| 11 | C. Selenium |
| 12 | A. Magnesium |
| 13 | B. Skeletal fluorosis |
| 14 | B. Iodized salt distribution |
| 15 | D. Calcium |
| 16 | B. Iron deficiency anemia |
| 17 | C. Hypokalemia |
| 18 | C. Copper |
| 19 | B. Hyperparathyroidism |
| 20 | A. Increased aldosterone secretion |