Vitamin A, also known as retinol, supports the body’s natural defense system against illnesses and infection from diseases like measles. But it does not prevent people from getting sick in the first place,

The health departments from all Bay Area counties urged people to get vaccinated against measles because of rising cases across the country.

Bay Area health officials came together Friday to urge residents in the region to get a measles vaccination if they never received one or if they avoided the disease as a child. In a statement, the Association of Health Officials said it was making the recommendation because measles cases are rising in the United States.