Vitamin D acts synergistically in the body depending, for its effectiveness, on the availability and effectiveness of other nutrients including magnesium, vitamin K, zinc, boron, vitamin A. The four day rotation of foods compels eating a wide variety of whole foods THAT DELIVER these nutrients to support the needed synergy.
Vitamin D is now recognized as a hormone(wide ranging roles and effects), made when sunlight turns a chemical in our skin into vitamin D3, which is then transformed primarily in the liver and kidneys into the active form. As it is fat soluble, unused vitamin D is stored in fat tissue (luckily for those winter months for those of us wearing parkas/hats/gloves..).
But there is increasingly thinking that Vitamin D is depleted in a significant number of people. Looking to remedy this with foods is a little challenging, as Vitamin D is found in relatively few foods. Here is a visual display of vitamin D food sources : including salmon, tuna, sole, pork ribs, egg yolk, shiitake mushrooms, beef liver, ricotta cheese. (The cereal suggestion on this link is fortified with vitamin D and so a form of supplementation.) See also Calcium and Vitamin D: Top Food Sources to Prevent Osteoporosis. In Canada and the Us, milk is fortified with vitamin D. Add these foods to your diet.
Vitamin D DRIs (daily intake for healthy populations) : Note the DRI’s reflect a proposal for minimal sun exposure, due to the public health concerns about skin cancer from sunlight : so while it appears total dietary intake of vitamin D in the North American population is indeed less than these DRI amounts, blood levels of vitamin D in the general population suggest that sun exposure is currently providing significant amounts of vitamin D to North Americans (Institute of Medicine, 2010). NOTE also the “tolerable upper intake levels” of vitamin D, as high levels of vitamin D supplementation (ie. above 4000 IUs per day for adults) apparently have health risks. HERE IS THE RISK IN SUPPLEMENTING WITH PILLS instead of EATING FOODS.
The Rotation Diet Plus©Software helps to manage complex diets. Consult a qualified health professional for any dietary change.