A -orange or red foods.  Apricots, carrots, peppers, sweet potato, squash.  Also dairy, eggs, oily fish, (famously) liver.

B1 (thiamine) – deficiency causes several different syndromes including Wernicke’s encephalopathy (confusion, ataxia, ocular) and dry (peripheral neuropathy) or wet (cardiac failure) beri-beri. Depends on chronicity.  Classically alcoholism or diet dependent on polished rice. Bread has it!

B6 – fish, potatoes, fruit, fortified breakfast cereal.

C – citrus, blackcurrant, kiwi, berries.  Also peppers, broccoli, Brussel sprouts, potatoes.

B12 – see Vitamin B12.  Found in fish, meat, eggs, milk, fortified breakfast cereal, yeast extract (Marmite).  So a major issue for vegans.  Deficiency classically causes macrocytic anaemia.

Curiously, teenagers often seem to have high levels in my experience.  Apparently this can be a flag for some nasties, namely malignancies, liver and kidney diseases, and can then be accompanied by symptoms of deficiency, due to disrupted pathways…  [QJM 2013]

E – nuts and seeds.

K – green leafy veg.

Folate (folic acid) – green leafy vegetables, broccoli, brussel sprouts.  Oranges, wholegrain cereals, nuts and pulses (peas, chickpeas, kidney beans)

Treatment

If vision loss or other neurological complications of malnutrition, can use IV or IM Pabrinex – vitamins B1,B2, B6, C, nicotinamide and glucose for intravenous or intramuscular administration.

Additionally, vitamins A and B12 may be replaced using high-dose intramuscular injections but may need unlicensed imported product.