Vitamins

Vitamins

Vitamin A

• Retinoic Acid is important in Rod and cone cells for vision
• Hair, skin, eyes = impt in night vision and blindness
• Necessary in PTH function → cofactor
• Impt. Component of CSF
• Deficiency:

• Night Blindness
• ↓ Ca²⁺ ↑ P = hypothyroidism
• Vitamin A Excess
• ↑↑ PTH Effect
• Moans, Groans → Pancreatitis
• Bones → PTH leaching bone
• Stones → Ca²⁺
• Excess production of CSF → pseudotumor cerebri = only cause of ICP that causes no herniation
• Presents with Headache and papilledema
• CT → Ventricle enlargement
• LP → ↑↑ pressure
• Treatment:
• Serial LPs to siphon excess CSF

Vitamin B1 (Thiamine) → TTP

• Pyruvate dehydrogenase
• α - keto glutarate dehydrogenase
• Branched Chain amino acid dehydrogenase
• Transketolase

Vitamin B1 Deficiecy:

• Wet Beri Beri = High output cardiac failure
• Dry beri beri = w/o heart failure
• Alcoholic = Wernickes encephalopathy (temporal lobe) - ataxia, nystagmus
• Korsakoff (Mammilary bodies) - confabulation, psychosis

Vitamin B2 (Riboflavin, FADH2)

• Angular cheliosis/stomatitis
• Best source = Milk, vegetables
• Sun can breakdown riboflavin → reason why milk is no longer stored in glass bottles
• Magenta colored tongue

Vitamin B3 = NIACIN

NAD/NADH

Niacin Deficiency

Pellagra = 3 Ds = Dementia, Diarrhea, Dermatitis, Death

Hartnups Disease presents very similar

o       A problem with the transport of Tryptophan → which is needed to make niacin

Trytophan

needed to make Niacin

Source = corn

Hartnups Disease = defective renal transport, similar to Pellagra

Vitamin B4 = Lipoic acid

Vitamin B5 = Pantothenic acid → CoA

Vitamin B6 = Pyridoxine

Cofactor for all TRANSAMINASES (AST/ALT)

INH pulls B₆ out of the body

Deficiency → neuropathy

Vitamin B12 = Cyanocobalamin

Use:

o       Methyl malonyl CoA Mutase = needed in prevention of myelin neuropathy

o       Homocysteine methyl transferase

Water soluble although absorbed in proximal ileum

Deficiency:

o       Dorsal column/Corticalspinal Tracts will be affect because they are the longest tracts therefore, need the most

o       Megaloblastic Anemia

Folate

Thymidine synthesis, purine synthesis.

1^st vitamin to run out in association with rapidly dividing cells

Deficiency:

o       Megaloblastic Anemia without neuropathy

o       Deficiency in pregnancy can cause neural tube defects in the fetus

o       Homocystienemia with risk of DVT and atherosclerosis

MCC

o       Alcoholics and pregnancy - body stores can be depleted in 3 months

Vitamin C

Scurvy - bleeding gums/hair follicles

o       Needed in:

Proline and lysl hydroxylase - collagen synthesis

Dopamine hydroxylase - catecholamine synthesis

Absorption of iron in GI tract

Vitamin D

Calcium absorption in Gut

Reabsorption of Ca²⁺ from kidneys

Osteoblastic activity → ↑ both Ca²⁺ and P

Decreased in Rickets

o       Children

o       Lateral Bowing of legs

Decreased in Osteomalacia = Soft bones

Vitamin D resistance Rickets

o       X-linked dominant ( Father → daughter)

o       Kidney is leaking phosphorus, so calcium goes with it

Vitamin E

anti-oxidant ( absorbs free radicals)

Skin, eyes, hair

Decreased in Retinopathy

Decreased in Alzheimers

Vitamin K

Clotting Factors 2,7,9,10, (1972) proteins C (shortest half life) & S

γ-carboxylation of these factors

Biotin

Cofactor for all CARBOXYLASES

Pyruvate carboxylase ( Gluconeogenesis/FA Syn)