Vitamin Deficiencies

Question 1

how does vitamin depletion occur?

Answer 1

inadequate itnake—> reduces cell stores—> evetnuaklly failure to maintain tisue levles

then biochemcia, function will be insuffient and eventuallu gey symptoms appearing.

Question 2

Describe Vitamin A defiiency sympotms?

Answer 2

night blindness

lesions of cornea , blindn ess (xeropthalmia)

increased susceptiiblity to infection

decreased immune unfction

impaired reproduction

Question 3

describe Xeropthalmia and night blinndess

Answer 3

abrnoaml dryness of the conjcitva and cornea od the eye with inflamation andridge formation- associate with vitamin A deficiency

first stage is night blindness

insuffient retinok reachin geye eeye- reduced rhodopsin

poor illumination- increased bleaching time bewttn rods bleeching

failure to constrict pupils

Question 4

what are the stages of Xeropthalmia

Answer 4

1. X1a (conucitval xerosis)- dryness loss of goblet cells
2. X1b0 bigots spot- mound of keratinised cells
3. XS- corneal scar
4. Xerophtlamaic fundus- whit spots/lesions on reitna can lead to total blindness

Question 5

what is the effect of vitamin A on immune fucntion?

Answer 5

iin chiuldren- masively increase suspceitbility of infection

imapiured maintenance of epithelial tissues- gut, rps, urogntial and conjcutiva- increase keratinisation and decreased mcuus

impaired ability to phagoctysose by neutrophils and macrophages

decreas number of NK cells

decrease antiobdy respones

Question 6

what causes rickets?

Answer 6

vitamin D deficienc

dley or failure of minerlaisation of the caritlagnous growjt plates in gorwing child.

height and weigh ususally belwo 3rd percentile

Question 7

what factors predispose children to reickets

Answer 7

high latitude

lack of sunlight exposure, overcrowidn,g social customs, clothing

infants with mother vitmain D deficineict

low dietary calcium intake

prolonged breast feeidnw without vitamin D supplementation

Question 8

what is the treatment of rickets?

Answer 8

oral: aggressive treatment inovlving calcium or vitmain D suppementation

IM- vitamin D injection every 6 months or year-( if chuidlr cannot take supplemtnby mouth or has intestinal/liver disease

Question 9

how can we prevetn Vitamin D deficinecy /rickets?

Answer 9

increase Vitmain D stores in mother

if exclucisvely breat feeding- must consume vitmain D suppleme t (5ug/day) oral drops

dormal feeds msut have Vitamin D added

half life of 25-hydroxyvitamin D (25-OHD) is 3-4 weeks so ababies stores depelte rapdily after birht

Question 10

what is vitamin D deficicneyc in adults lead to?

Answer 10

osteomalacia

failure of bone minerasialtion as an excess of poorlt calciuied osteroiod

Question 11

how does vitamin E deficiency present?

Answer 11

mild deficinecy- dermatitis

Severe- neiuropathy and hameorhaging

linked to selenium mineral

Question 12

what is this?

Answer 12

scurvy0 vitamin C defiifncye

general weakness, anemai, gingivitis- gum disease and skin ahemorhages

rarely seen in uk now

Question 13

how would vitamin K deficiency present ? and what is the most likely cause

Answer 13

invovled in blodd clotting

classic signs are increase prothrombin (clottin time)

lead to haemorrhagci eveent

only occurs when very low-

usualy causes by GI dirsorder rather than intake

cystic fibrpsi, IBD , chronic pancreatiti, liver disease, soem antibiti users

Question 14

which group is most at risk of Vitamin K deficiency?

Answer 14

new borns most at risk

Haemorrhagic disease of new born

poor placental transfer, hepatic immaturity, low vitamin K contne tin breats milk

prevented by vitamin K (oral or Im injection) within first 6 hours of birth

Question 15

what are B vitamins?

Answer 15

co-enzymes in energy metabolism

Question 16

what is the cause of Beri-beri?

Answer 16

B1 thiamine deficiency

impaired muscle contractiosn, cardia cfucntion, oedema (wet beri beri)

devrease nerulogical funcrion (dry beri-beri)

heavy alcohopl cpmnsumption with poor food intake - alcohol interupts absorption (wernickes koraskoff syndrome)

Question 17

hwo would B2- ribroflavin deficinecy present

Answer 17

ariboflavinosis

inflammation of mucus membranes of the oral cavity and pharynx

deficiencies are rare

drug and alcohok suffers and restrcited calroies intake

Question 18

what is the cause of pellagra

Answer 18

nacin - B3 defgiicnecy

dermatitis- red flaky skin areas of dislcopration, rangin from red to brown

thoick, crutsy, sclay or cracked skin

ithcy, bruning. patches of skin

niacin is bound by protien

found in meats and fish

Question 19

describe vitamin B 12 defifinecy

Answer 19

perncious anaemia (bone amrrow cells become abnroamlly large and neutrophils dveelop multi-lobed nucleal) megalobastlic RBC- continue to grow dont lose nuclei

rare as batcerial syntheiss in the gut

\demyelination of nerves -

Question 20

how woudl folate deficiency manifest differently to B12

Answer 20

both result in megalobastic anameia

but Folate deficneicy would have no effect on myelination