IMED1004 Vitamins and deficiency Exam Questions and Answers Solved Correctly Rated A+
Vitamin A deficiency - Answers Deficiency = teratogenic (developmental malformity in baby when
pregnant), blurred vision, excessive bone growth, anaemia, night blindness
Vitamin D deficiency - Answers Caused by provitamin (inactive) malabsorption, lack of UV exposure.
Deficiency = osteomalacia (bone softening), impaired bone formation.
Vitamin E deficiency - Answers Lipid soluble. Deficiency = peripheral neuropathy, anaemia. Role as
antioxidant, prevents oxidation of PUFA (polyunsaturated fats)
Vitamin A - Answers Family of retinoids (with carotene provitamin and different vitamers). Functions:
light receptor vision signalling via opsin, control of gene expression by activating receptors RAR/RXR
which bind DNA.
Vitamer - Answers definition + example
Provitamin - Answers A compound that can be converted by the body into a vitamin (becoming active).
E.g. alpha, beta, gamma carotene
What is a vitamin - Answers An essential micronutrient (small amounts consumed for normal
physiological function) that must be taken through diet. Organic compounds.
Lipid soluble vs water soluble vitamins - Answers Lipid soluble - A,D,E,K. Water soluble - B,C. Water
soluble vitamins are not readily stored - daily intake required. Lipid soluble vitamins can accumulate in
body by being stored in liver, adipose tissue (fat stores). Risk of being stored excessively
Vitamin A toxicity - Answers Caused by rare dietary habits (eating livers), or via medication, e.g.
accutane. Symptoms include teratogenic influence on embryo, idiopathic increased inter-cranial
pressure
Activated vitamin = ready to be absorbed - Answers
Vitamin D - Answers Activated form (ready to be absorbed) = calcitriol. Involved in Ca2+ homeostasis
mediated by PTH. PTH promotes formation of active vitamin D, which increases Ca2+ absorption.
Regulated by negative feedback - high Ca2+ = inactivated PTH (via inhibitory TF preventing
transcription&translation as PTH is a peptide).
Vitamin K - Answers Includes K1, K2 (active forms = vitamers of family K). In plants as electron acceptor
for photosynthesis, also found in fermented foods. Function = activation of Gla proteins
Activation of Gla proteins and function - Answers Activated by vitamin K in oxidised quinone form.
Vitamin K provides reducing power, acting as a cofactor for carboxylase enzyme converting Glu to Gla
proteins by adding a second carboxyl group to Glu. Gla proteins are useful as can bind Ca2+.
Vitamin A deficiency - Answers Deficiency = teratogenic (developmental malformity in baby when
pregnant), blurred vision, excessive bone growth, anaemia, night blindness
Vitamin D deficiency - Answers Caused by provitamin (inactive) malabsorption, lack of UV exposure.
Deficiency = osteomalacia (bone softening), impaired bone formation.
Vitamin E deficiency - Answers Lipid soluble. Deficiency = peripheral neuropathy, anaemia. Role as
antioxidant, prevents oxidation of PUFA (polyunsaturated fats)
Vitamin A - Answers Family of retinoids (with carotene provitamin and different vitamers). Functions:
light receptor vision signalling via opsin, control of gene expression by activating receptors RAR/RXR
which bind DNA.
Vitamer - Answers definition + example
Provitamin - Answers A compound that can be converted by the body into a vitamin (becoming active).
E.g. alpha, beta, gamma carotene
What is a vitamin - Answers An essential micronutrient (small amounts consumed for normal
physiological function) that must be taken through diet. Organic compounds.
Lipid soluble vs water soluble vitamins - Answers Lipid soluble - A,D,E,K. Water soluble - B,C. Water
soluble vitamins are not readily stored - daily intake required. Lipid soluble vitamins can accumulate in
body by being stored in liver, adipose tissue (fat stores). Risk of being stored excessively
Vitamin A toxicity - Answers Caused by rare dietary habits (eating livers), or via medication, e.g.
accutane. Symptoms include teratogenic influence on embryo, idiopathic increased inter-cranial
pressure
Activated vitamin = ready to be absorbed - Answers
Vitamin D - Answers Activated form (ready to be absorbed) = calcitriol. Involved in Ca2+ homeostasis
mediated by PTH. PTH promotes formation of active vitamin D, which increases Ca2+ absorption.
Regulated by negative feedback - high Ca2+ = inactivated PTH (via inhibitory TF preventing
transcription&translation as PTH is a peptide).
Vitamin K - Answers Includes K1, K2 (active forms = vitamers of family K). In plants as electron acceptor
for photosynthesis, also found in fermented foods. Function = activation of Gla proteins
Activation of Gla proteins and function - Answers Activated by vitamin K in oxidised quinone form.
Vitamin K provides reducing power, acting as a cofactor for carboxylase enzyme converting Glu to Gla
proteins by adding a second carboxyl group to Glu. Gla proteins are useful as can bind Ca2+.
