Micronutrients Flashcards
What is the chemical name for Vitamin B1?
Thiamine
What is the role of thiamine?
Precursor to thiamine pyrophosphate, cofactor for pyruvate dehydrogenase (Pyruvate to acetyl CoA) and alpha-ketoglutarate dehydrogenase (alphaketoglutarate to succinyl CoA)
What is the chemical name for vitamin B2?
Riboflavin
What is the role of riboflavin?
Precursor of FAD (cofactor of glutathione synthase + electron carrier in krebs cycle) and FMN (cofactor of NADH dehydrogenase)
What is the chemical name of vitamin B3?
Niacin
What is the role of Niacin
Primary constituent of the coenzymes NAD+ and NADP+
Required for nutrient metabolism including cholesterol and fatty acid synthesis
What is the chemical name of Vitamin B6?
Pyridoxine
What is the role of pyridoxine?
Component of pyridoxal phosphate:
—involved in glycolysis, gluconeogenesis and lipid metabolism
—Synthesis of neurotransmitters
—Synthesis of haeme protein (specifically porphyrin synthesis)
—Immune function (specifically production of interleukin 2)
Consequences of thiamine deficiency?
Wernicke Syndrome: — ophthalmoplegia — sixth nerve palsy — nystagmus — ptosis — ataxia — confusion — coma —> death
Korsakoff’s psychosis
— where confusion persists after thiamine deficiency has been treated
Consequences of riboflavin deficiency?
Anaemia
Thyroid disfunction
Eye disease
Stomatitis
Consequences of niacin deficiency?
4 Ds: — Diarrhoea — Dermatitis — Dementia — Death
Consequences of pyridoxine deficiency?
Infants —> convulsive seizures
Adults —> confusion, depression, insomnia
Anaemia
Difficulty walking, weakness
What is the chemical name for vitamin B9?
Folic acid
What is the role of folic acid
Precursor for tetrahydrofolate used in purine and pyrimidine synthesis, and amino acids
Consequences of folic acid deficiency? What about during pregnancy?
Megaloblastic anaemia
Diarrhoea
Neurological symptoms
Pregnancy: important for proper neural tube closure of foetus, so deficiency can lead to defects like spina bifida
What is the role of vitamin B12?
Coenzyme in reaction converting methylmalonyl CoA —> succinyl CoA, leading to neurotoxic build up of methylmalonic acid
Coenzyme in methionine synthesis from cysteine
Consequences of vitamin B12 deficiency?
Megaloblastic anaemia
Neurological change
Depression and irritability
Dietary intake of zinc?
4-14 mg/day
Dietary intake of copper?
1.2mg/day
Dietary intake of iron?
8.7mg/day
Young women = 14.8mg/day
Zinc roles?
Nutrient metabolism
Immune system function
Reproductive system development
DNA and RNA polymerase activity
Copper roles?
Important component of cytochrome C
Required for superoxide dismutase
Involved in connective tissue synthesis
Involved in regulation of gene expression
Iron roles?
Haemoglobin synthesis
Cytochrome activity
Required in urea cycle activity
Required for cholesterol biosynthesis
