Vodka

Vodka is notable for histamine, salicylate and gluten. Clear on tyramine, sucrose, FODMAPs, lactose, oligosaccharides, sorbitol, fructose, nickel and oxalates.

Vodka contains moderate levels of histamine. Vodka is distilled to the highest purity of any spirit and filtered afterwards, so it carries essentially nothing but ethanol and water - no histamine survives a still. The ethanol is the whole problem: it blocks DAO, so the vodka is not the source, it is the handbrake on everything else in the meal.

Vodka contains moderate levels of salicylate. Distillation leaves very little salicylate behind, so vodka is here almost entirely for alcohol's own effect — increased gut permeability and slower salicylate clearance. Neither study publishes a value for this particular drink.

Vodka contains only low levels of gluten. Vodka is gluten-free even when it is made from wheat, and the reason is physical: gluten is a protein, protein does not evaporate, and only the vapour leaves a still. The grain on the bottle tells you about the flavour, not about the gluten. The law says it in one line, and the line is worth quoting: Annex II exempts 'cereals used for making alcoholic distillates including ethyl alcohol of agricultural origin' from the gluten declaration. An exemption is a judgement about the process, not a measurement of the bottle - which is why what is added AFTER distillation is still the open question. Amounts vary by brand and recipe, so always check the label of the exact product.