Vitamin D2 and vitamin D3 are the forms of vitamin D most important to human health, according to the Mayo Clinic. Vitamin D2 is manufactured by plants, while vitamin D3 is manufactured in the skin when it's exposed to the sun.
Population in families living in Washtenaw County ; Total Population: 238,069; Population Under 18 years: 70,878; Population 18 years and over: 167,191
Cass County, Michigan. Cass County is a county in the U.S. state of Michigan. As of the 2010 census, the population was 52,293. Its county seat is Cassopolis. Cass County is included in the South BendâMishawaka, IN-MI, Metropolitan Statistical Area which has a total population of 316,663 and is sometimes considered part of Greater Michiana.