People who should avoid beetroot include:

• Individuals prone to kidney stones, due to high oxalate content in beetroot which can contribute to stone formation.
• People with low blood pressure, as beetroot’s nitrates can further lower blood pressure and worsen hypotension.
• Diabetics, since beetroot contains sugar that might impact blood sugar levels if consumed in excess.
• Individuals with iron overload disorders like hemochromatosis because beetroot is high in iron.
• Those with gastrointestinal issues such as irritable bowel syndrome, as beetroot may cause bloating, gas, or digestive discomfort.
• People with beetroot allergies, which though rare, may cause rash, itching, breathing difficulty, or more severe reactions.
• Patients on medications that affect blood pressure or blood thinning, where beetroot could interact with the medication effects.

Additional caution is advised for pregnant women, children under three months (due to nitrate poisoning risk), and those with low calcium levels or liver issues from excess intake.