This information was obtained from Dr. Dan Murphy.
Epidemiology and Infection October 2007, Vol 135, No. 7, pp. 1095-1098 "There is an epidemic of vitamin D insufficiency in the United States, the public health impact on this observation could be great." "Over a 3 year period, taking 800 IU (per day) of vitamin D3 reduced the incidence of colds and flus by 70%. Taking 2000 IU (per day)of vitamin D3 reduced the incidence of colds and flus to nearly zero (only one case out of 104 users)."
Vitamin D Supplementation and Total Mortality A Meta-analysis of Randomized Controlled Trials Archives of Internal Medicine September 10, 2007;167:1730-173 "Low Vitamin D status could be associated with higher mortality from life-threatening conditions including cancer, cardiovascular disease, and diabetes mellitus that account for 60% to 70% of total mortality in high-income countries." "Vitamin D influences both incidence and survival of cancer."
Vitamin D intake and incidence of multiple sclerosis NEUROLOGY, January 13, 2004;62:60-65 "Taking vitamin D supplements for more than 10 years lowered the risk of developing MS by 59%." Vitamin D supplements in the first year of life reduces the risk of Type-1 Diabetes." "Vitamin D has strong immunoregulatory effects." "There is no reduced risk of MS with increased Vitamin D intake from food. It had to be in the form of supplements."
And Finally...Vitamin D for Cancer Prevention: Global Perspective Annals of Epidemiology Volume 19, Issue 7, July 2009, pp 468-483 "Vitamin D3 serum levels of 40 to 60 ng/mL would prevent three fourths of deaths from breast and colorectal cancer in the US and Canada." "Raising Vitamin D3 level 40 to 60 ng/ml would require supplementation with about 2,000 IU of vitamin D3 per day. "There is no reasonable risks from intake of 2,000 IU per day of vitamin D3.""
Vitamin D3 is a must take supplement. The positive effects on the immune system are nothing short of stunning. Vitamin D2 is not the same as Vitamin D3 so be sure you are purchasing Vitamin D3.