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
Allegan County is an area in Allegan County, West Michigan, Michigan with a population of  111,696. There are 55,678 male residents living in Allegan County and 56,018 female residents. The total number of households is 41,996 with 2.64 people per household on average. Total household expenditures in Allegan County are below the national average. The median age of the current population is 38.29 with 42,906 people being married and 31,695 being single. The employment numbers show that there are 51% white collar employees and 49% blue collar employees in Allegan County.