Quote by William Davis
““therefore advise people to take 4,000 to 8,000 international units (IUs) per day of oil-based vitamin D3, or cholecalciferol, in gelcaps or drops, for assured absorption. This dose is sufficient to achieve a 25-hydroxy vitamin D blood level of 60 to 70 ng/mL after 2 to 3 months of supplementation in the majority of people, just like a young lifeguard with a tan.””
