Is 25000 IU of vitamin A too much? Understanding the risks of hypervitaminosis
                                
                                
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                                    3 min read                                
                            
                                According to the National Institutes of Health, the tolerable upper intake level (UL) for preformed vitamin A in adults is 10,000 IU per day. Taking 25000 IU of vitamin A daily over the long term is considered potentially toxic and significantly exceeds this safe limit.