Includes bibliographical references (pages 273-291) and index.

From NASA to the National Zoo -- The light of your life and the health hormone. What is vitamin D? : is it a hormone or a vitamin? ; Fish, phytoplankton, dinosaurs, lizards, and you : the evolution of vitamin D and the science of sunlight ; Hard bodies : the magic of D on muscle and bone health ; Adventures in globe-trotting : do common killers like cancer and heart disease share common geography? ; Finding immunity : can vitamin D be the body's secret weapon against germs and autoimmune disease? ; Mind matters and mixed emotions : the facts of light on mood, mental states, and sense of well-being ; Are you deficient? " a quick self-test to determine your level of deficiency -- Three steps to rebuilding your vitamin D levels. Step 1 : let the sunshine in : practicing sensible sun exposure for optimal health ; Step 2 : Bone up on calcium : the dynamic duo of calcium and vitamin D can sustain your life ; Step 3 : supplement safely : how to supplement as a backup plan ; Special treatment : other causes of vitamin D deficiency ; Dethroning the cover-up : another giant leap for medicine and mankind ; Q & A : odds and ends and a few more reminders in the classic FAQ style.