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
Tuscola County, Michigan. Tuscola County is a county located in the Thumb region of the U.S. state of Michigan. As of the 2010 census, the population was 55,729. The county seat is Caro. The county was created by Michigan Law on April 1, 1840, from land in Sanilac County and attached to Saginaw County for administrative purposes.