What is the potential importance of taking vitamin A?

Dietary deficiency of vitamin A is uncommon in healthy people except in older age groups. Although vitamin A is important for the function of the immune system, vitamin A supplementation did not help prevent infections in elderly people living in nursing homes, in one study.⁸ Due to concerns about birth defects and bone loss, people should not take over 10,000 IU of supplemental vitamin A in the form of retinol without consulting a doctor.