What vitamin deficiency causes bumpy skin on arms?
                                
                                
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                                    4 min read                                
                            
                                Keratosis pilaris (KP), the harmless skin condition often resulting in bumpy, rough skin, affects a significant portion of the population, with estimates suggesting up to 40% of adults and 50-80% of adolescents experience it. While genetics is the primary underlying factor for KP, a vitamin deficiency causes bumpy skin on arms and other affected areas by interfering with the normal processes of skin cell renewal.