Dr Michael Holick is arguably the preeminent vitamin D researcher of the past 30 years. A search of the ISI Citation Index for “M.F. Holick and Vitamin D” lists 389 peer-reviewed scientific papers that he has authored or co-authored. These papers have been cited by other researchers an incredible 13,000 times, which indicates his huge contribution to the field of vitamin D research.
The Vitamin D Solution is a synopsis of the current state-of-the-art in vitamin D research. The impact of vitamin D on health is profound and goes way beyond absorption of calcium (although that is important). There are vitamin D receptors in every single cell in the body, with far-reaching effects on a whole host of cellular processes within the body.
It’s a good news/bad news/good news story. The good news is that vitamin D can prevent and treat a host of diseases including heart disease, cancer, type 1 and 2 diabetes, tooth decay, multiple sclerosis, obesity, depression and dementia, amongst others. The bad news is that we are overwhelmingly deficient in vitamin D. This includes the majority of young women and their babies, with enormous implications for childhood development and health. Vitamin D deficiency is so widespread that Dr Holick uses the alarming term “pandemic”. The good news is that vitamin D deficiency can be alleviated through sensible sun exposure and/or inexpensive supplements.
In case you are unaware, vitamin D, which is actually and hormone and not strictly a vitamin, is produced naturally by the skin through exposure to sunlight (specifically the tanning UVB rays). Vitamin D can also be obtained through diet, although this amount is very small in a typical North American diet. Vitamin D supplements and sensible sun exposure are recommended. Dr Holick describes the various provitamin, circulating and active forms.
The current recommended daily intake of vitamin D of 400IU is described as woefully inadequate. Dr Holick recommends that, in addition to sensible sun exposure, children and adults supplement with 1000-2000IU of vitamin D per day to maintain optimal blood levels. Pregnant women and obese individuals require considerably more. He considers that the “upper tolerable level” of vitamin D that can be consumed with absolute safety is upwards of 10,000IU per day.
Dr Holick takes square aim at the anti-sun zealots, especially his dermatology colleagues. In fact, in 2004 he was forced to resign from his position as Professor of Dematology at Boston University School of Medicine for recommending modest and sensible sun exposure, and condoning the responsible use of tanning beds.
The book is divided into 2 parts. The Part I covers the science and history of vitamin D research and its role in disease and in animal and human evolution. This includes a checklist to determine whether you are a candidate for vitamin D deficiency, and the appropriate blood test for the major circulating form of vitamin D (the test is referred to as serum 25(OH)D test). Optimal ranges for the serum vitamin D levels are 40-60 ng/ml, and deficient is defined as less than 20 ng/ml.
Part II describes three steps to maintaining or rebuilding your vitamin D levels, which are (1) sensible sun exposure, (2) adequate calcium intake along with good dietary sources of vitamin D, and (3) vitamin D supplementation. Dr Holick refers to vitamin D and calcium as the dynamic duo (research from Europe and Japan would also include vitamin K2 as the terrific trio).
There is also an excellent and very informative Q&A section.
My own personal grumble is that there is no mention of Sir Edward Mellanby or his wife Lady May Mellanby and their groundbreaking research in Britain during the 1920’s and 30’s, which included the discovery of vitamin D in cod liver oil, dietary cure for the childhood bone disease rickets, and Lady Mellanby’s use of vitamin D to treat tooth decay.
I give The Vitamin D Solution 4 out of 5 stars. It is certainly required reading for those of us who are interested in health and nutrition and taking responsibility for our family’s health. It provides a clear prescription for how to get tested for vitamin D levels, and what to do to rebuild and maintain optimal levels. This book would appeal to the more science-oriented reader. Others may find it a little overwhelming. There is a vast bibliography for those of us who like to check the original references.
If you prefer not to wade through the science, you might do with a very user-friendly summary and review in November’s Oprah magazine.