Understanding What is the TUL for Vitamin D
                                
                                
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                                    3 min read                                
                            
                                According to the NIH, the Tolerable Upper Intake Level (UL) for most adults is 4,000 IU (100 mcg) of vitamin D per day. Knowing what is the TUL for vitamin D is crucial for preventing toxicity, a rare but serious condition resulting from excessive supplementation.