Is Giant horsetail Poisonous

Giant horsetail should be avoided; eating it, especially in large quantities, exposes the body to a dangerous toxin called thiaminase. Thiaminase, which exists in all tissues of this plant, robs the body of B vitamins and can cause a dangerous deficiency if enough is eaten. The B complex of vitamins is essential to many body functions, including proper brain, nerve, and muscle functions. Those muscles include the heart. Symptoms of vitamin B deficiency include fatigue, confusion, mouth lesions, rashes, lowered immune response, depression, anxiety, anemia, neurological damage, weakness, numbness or pins and needles in the hands and feet, balance problems, coordination problems, weakness, nausea and cramps, and eventually collapse, coma and possibly death. Keep small children away from this plant. If someone ingests it and starts showing symptoms, get them to a doctor immediately.