Vitamin A toxicity
- Majority due to chronic ingestion of synthetic vitamin A
- Toxic dose is approximately 10x higher than Recommended Dietary Allowance (RDA), totaling ~50,000 units
- Provitamin A (beta-carotene) ingestion very unlikely to cause toxicity
- Carotenemia common in children eating leafy green vegetables or carrots, with spontaneous resolution after cessation of foods
- Single dose >660,000 IU (>200,000 micrograms)
- Symptoms include nausea/vomiting, vertigo, blurry vision
- Greater than x10 amount of RDA
- Symptoms include: skin irritation, alopecia arthralgias/bone pain, hyperlipidemia, hepatotoxicity, ataxia, visual impairment, headache, pseudotumor cerebri, elevated ICP
Retinoic acid in 1st trimester
- Very teratogenic
- Spontaneous abortions and fetal malformation
- Vitamin A in pregnancy safe upper limit 10,000IU
- Vitamin A stored in liver-circulating vitamin A will likely not reflect vitamin A stores
- Measurement of serum retinyl esters more accurate in fasting state
- Discontinue high vitamin A intake
- Most fully recover
- Vitamin E supplementation
- Manage complications of liver failure
- Liver transplant may necessary in severe toxicity w/fulminant liver failure
- Consider tox or poison control consult
- Dependant on severity
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- Krasinski SD, Russell RM, Otradovec CL, et al. Relationship of vitamin A and vitamin E intake to fasting plasma retinol, retinol-binding protein, retinyl esters, carotene, alpha-tocopherol, and cholesterol among elderly people and young adults: increased plasma retinyl esters among vitamin A-supplement users. Am J Clin Nutr 1989; 49:112.