In September 2011 Dr. Cannell wrote a piece titled “Why Should You Keep Your Vitamin D Level Around 50ng/ml? https://www.vitamindcouncil.org/blog/why-should-you-keep-your-vitamin-d-level-around-50-ngml/. “Why should you keep your vitamin D level around 50 ng/ml?” “Four different sources, using four different rationales, and four different lines of reasoning, all lead to the same conclusion”. 1. Our closest “simian relative” the chimpanzee, has levels between 40 -60 ng/ml (Reinhold Veith) 2. Lifeguards in summer have 40 -60 ng/ml levels without supplements. 3. It takes a Mother having a level of between 40 -60ng/ml herself to then have Vitamin D show up in breast milk for her baby. (Professor Bruce Hollis and Carol Wagner) 4. Humans do not “store” Vitamin D until they reach a level of 40ng/ml. (Professor Robert Heaney) Of course since he wrote that there are a lot more studies and information that have shown a higher amount then 30ng/ml is very beneficial and prevents diseased states. The incidence of cancers increase at 30ng/ml and below. Does that help?