Do not take Synthroid within 4 hours of ingesting medications, supplements, or foods that may interact with Synthroid. Antacids
, iron, and
calcium supplements, dietary fiber, soy, and even walnuts can affect your body's absorption of Synthroid. Talk to your doctor to learn more."
Note that both sites clearly say to avoid antacids, iron and calcium "supplements" for 4 hours. There's not enough iron OR calcium in most foods to warrant not eating them, because of thyroid med.