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
In 1978, Bay County became the second Michigan county (after Oakland County) to adopt a County Executive form of government.s of the 2010 census, the population was 107,771. The county seat is Bay City. Bay County comprises the Bay City, MI Metropolitan Statistical Area, which is included in the Saginaw-Midland-Bay City, MI Combined Statistical Area.