This excerpt it taken from Dr. Dean's Total Body Immunity eBook:
Vitamin D researchers, including GrassrootsHealth agree that the dosage of vitamin D should be based on the blood levels of the vitamin and they’re come up with a nifty Vitamin D Calculator to help you figure out how much you require to reach a certain level. For the average individual, 40-60ng/mL is desirable, but if you want to avoid breast cancer or breast cancer recurrence, you will need to strive for a higher level above 60ng/mL.
Click on this link for The Vitamin D*Calculator
Enter: Current Weight in lbs; Current Serum Level in ng/mL; Desired Serum Level ng/mL; Calculate and you will see the amount of vitamin D you will have to take to achieve your goal.
Consistent Daily Dosing
With this knowledge, researchers are beginning to realize that the frequency of dosing matters. For disease prevention and treatment, daily dosing (food, sun, and supplement) is very important! It’s only in the past 10 years that the focus has shifted from bone health to autoimmune disorders, cancer, cardiovascular disease, and infections that the importance of dose timing has been uncovered.