I read recently that vitamin supplements are harder for the body to absorb if taken with a high-fiber meal. This concerns me since I take mine with my morning bowl of oatmeal or bran cereal. Also, does it matter what time of day I take them? (I take a multivitamin/multimineral, as well as calcium tablets and vitamin E capsules. I also take a vitamin C supplement during cold and flu season.) Any advice?
Nutritional supplements are generally best absorbed when taken in divided doses together with meals. However, some types of dietary fiber can bind certain minerals (such as calcium, copper, iron, magnesium, selenium and zinc), thus reducing their absorption and availability to the body. Although there is some evidence that the body may gradually learn to absorb these minerals as it adjusts to a high-fiber diet, it may be preferable to take your vitamins in the morning with your high-fiber breakfast, and save your minerals for the late evening. (You may wish to take half of your vitamin C in the late evening to improve around-the-clock protection from the common cold.)
My recommendation is different if you are low in stomach acid (a common condition in people age 60 and older). In that case, you may have better absorption if you take your minerals with food, as food stimulates the production of stomach acid, which, in turn, helps minerals to be better absorbed.
Since everybody is different, different forms of supplemental vitamins and minerals have different characteristics, and some questions about supplement absorption are still unanswered. These recommendations are simply my best educated guesses as to what schedule will provide you with the best absorption.