Can't you drink tea at all on days when taking iron supplements?

Generally speaking, it is not necessary to avoid tea entirely for the entire day when taking iron supplements. The key is to avoid drinking tea 1–2 hours before and after taking the medication, to prevent tea from interfering with iron absorption. Drinking moderate amounts of tea at other times is usually not a problem. Here's a detailed explanation:

Tea contains tannic acid, which can bind with ferrous iron in iron supplements to form insoluble precipitates that are difficult for the body to absorb, thereby reducing the effectiveness of iron supplementation. If tea is consumed within 1–2 hours before or after taking iron medication, this binding effect becomes more pronounced and may significantly impair iron absorption. However, during other periods—after the iron has been mostly absorbed by the body—drinking weak tea in moderation results in minimal impact from tannic acid on already-absorbed iron, and generally does not cause adverse effects. It is important to note, however, that strong tea should be avoided, as it contains higher levels of tannic acid. Even outside medication times, excessive consumption may have minor negative effects on metabolism.

In addition to avoiding tea around the time of taking iron supplements, it is recommended to consume foods rich in vitamin C, as vitamin C enhances iron absorption. Iron supplements are also best taken after meals to reduce irritation to the gastrointestinal mucosa. In daily life, properly scheduling the timing of medication and tea consumption can ensure effective iron supplementation while still allowing enjoyment of tea.