The iron overload condition is called Hemochromatosis. It is usually occurs in people that are genetically predisposed to it. There is more press on this condition due to the increased iron in our diets such as red meats and bakery items made with fortified flour. More people are getting that condition due to our fortified diet. Read the side panel of about every breakfast cereal, those figures don't occur naturally in the grains. You'll find them in the ingredients. Vitamin D is added to milk due to the occurance of rickets usually during wintertime (softening of the bones, bowleggedness) in my parent's generation (born 1920's). It is usually the minerals (iron, zinc, copper, iodine, etc) that are the culprits. The vitamins usually not. Vitamin C is needed daily and self destructs as it is used and is not stored by the body. Your furry four-legged friends make their own Vitamin C and D using sunlight. We can make our own D, but you need plenty of sun, especially in winter.
My generation, the Boomers, were not allowed to go outside anytime during the winter without a heavy coat here in my town. Nowadays, myself and most others in town go outside, in shirtsleeves, to do chores, etc. with the temps in the low 40's, sunny and no wind. But if it is 55, cloudy and windy, it really cuts into you. I have shoveled snow and took my coat off because I gotten too hot on those sunny days. But not last week though, the -7 temps were going through my thick gloves!
A blood panel I get every year will show the effects of the vitamin related disorders. I have gotten no negatives on these. If your physician gives you your regular blood test, especially if your are taking HRT, it will show. I don't take vitamins myself, but I know a few people that have these conditions who take vitamins. Take care!
Joelene