Vitamin A: Chronic daily vitamin A intakes in excess of 10,000 IU or weekly intakes in excess of 25,000 IU have resulted in hypervitaminosis A.
Excessive vitamin A intake (more than 10,000 IU daily) is hazardous during the first and second trimesters of pregnancy because it may lead to birth defects such as cleft palate, heart abnormalities and brain malformations, e.g., hydrocephalus and microcephaly (baby with a very small head).
Iron: Acute iron overdosage (e.g., intake of ≥1,500 mg elemental iron for a 50 kg adult) can be divided into four stages: Stage I: Occurs up to six hours after ingestion, the principal symptoms are vomiting and diarrhea. Other symptoms include hypotension (low blood pressure), tachycardia (rapid heartbeat) and central nervous system (CNS) depression ranging from lethargy (sleepiness) to coma (state of unconsciousness).
Stage II: May occur 6 to 24 hours after ingestion and is characterized by a temporary remission or signs of overdosage are decreased.
Stage III: Gastrointestinal symptoms recur accompanied by shock, metabolic acidosis (increased acid in the blood), coma, hepatic necrosis (death of liver tissue), jaundice (yellowish color of the skin, eyes and other tissues), hypoglycemia (low blood sugar), kidney failure, and pulmonary edema (fluid in the lungs).
Stage IV: Occurs several weeks after ingestion and is characterized by gastrointestinal obstruction (blockage) and liver damage.
Zinc: Rare occurrences of acute zinc poisoning have been reported. The toxicity signs observed after ingestion of high zinc doses (4-8 grams) include nausea, vomiting, diarrhea, fever, metallic taste, and lethargy.
If the patient has taken more than the recommended dosage, consult a doctor or contact a Poison Control Center right away.