Vitamin Deficiencies

Mnemonic

The B vitamins, numbered with their deficiency syndrome:

• B1 thiamine - beriberi and Wernicke-Korsakoff
• B2 riboflavin - angular stomatitis, cheilitis
• B3 niacin - pellagra: the three Ds, Dermatitis, Diarrhoea, Dementia, and death if untreated
• B5 pantothenate - burning feet
• B6 pyridoxine - sideroblastic anaemia, peripheral neuropathy, seizures. Depleted by isoniazid
• B7 biotin - dermatitis, alopecia
• B9 folate - megaloblastic anaemia, neural tube defects
• B12 cobalamin - megaloblastic anaemia plus subacute combined degeneration

“Folate makes you anaemic, B12 makes you anaemic and neurological”, which is why B12 must be replaced first: folate alone can precipitate cord degeneration.

Vitamin C deficiency is scurvy: perifollicular haemorrhage, corkscrew hairs, bleeding gums and poor wound healing, from failure of collagen hydroxylation.

Expansion

Fat soluble (A, D, E, K) - absorbed with fat, so deficient in cholestasis, pancreatic insufficiency and coeliac disease

• A: night blindness, xerophthalmia, keratomalacia. Excess is teratogenic
• D: rickets and osteomalacia
• E: haemolysis, ataxia and neuropathy
• K: bleeding with a prolonged prothrombin time; haemorrhagic disease of the newborn

Water soluble

• B1 thiamine: wet beriberi (high output cardiac failure), dry beriberi (neuropathy), and Wernicke encephalopathy (confusion, ataxia, ophthalmoplegia) progressing to Korsakoff psychosis
• B2 riboflavin: angular stomatitis, glossitis
• B3 niacin: pellagra, the three Ds of dermatitis, diarrhoea and dementia
• B6 pyridoxine: neuropathy, classically with isoniazid
• B9 folate: megaloblastic anaemia, neural tube defects
• B12: megaloblastic anaemia and subacute combined degeneration
• C: scurvy, with perifollicular haemorrhage, corkscrew hairs, bleeding gums and poor wound healing

Always give thiamine before glucose in a malnourished or alcohol-dependent patient, since a glucose load consumes remaining thiamine and can precipitate Wernicke encephalopathy.