diet
4 interactions related to diet
lithium + sodium
Lithium and sodium are handled by the same renal transporters and compete for reabsorption in the proximal tubule. A low-sodium diet causes the kidneys to retain sodium and lithium, raising lithium levels and the risk of toxicity; a sudden high-sodium load can drop lithium below the therapeutic range.
levothyroxine + fiber
Dietary and supplemental fiber can adsorb levothyroxine in the gut and reduce its bioavailability, leading to higher TSH and unstable dosing when fiber intake is high or variable. The effect has been demonstrated with high-fiber diets and pharmaceutical fiber supplements such as psyllium.
fermented foods + maois
Fermented foods accumulate tyramine through microbial decarboxylation of tyrosine during fermentation, and MAOIs block the monoamine oxidase enzyme that normally clears tyramine from the gut and bloodstream. Unmetabolized tyramine then triggers massive norepinephrine release, which can produce a hypertensive crisis with systolic blood pressure spiking above 180 mmHg.
tofu + levothyroxine
Tofu is made from coagulated soy milk and is one of the most concentrated sources of soy protein in the typical diet, with roughly 20 grams of soy protein per cup. Soy protein binds levothyroxine in the gut and reduces absorption by 16 to over 35 percent depending on dose, and case reports describe TSH rising when tofu is added to a previously stable levothyroxine regimen.