Do you need to take supplements?
Supplements cannot take the place of healthy diet. However, a growing amount of research suggests that a daily multivitamin provides a useful complement to a healthy diet (Willett & Stampfer, 2001, see references at end of page). In addition to ensuring an adequate intake of essential nutrients, a daily multivitamin is associated with lower risk of cardiovascular disease, colon cancer, and breast cancer (Willett & Stampfer, 2001). While all individuals may benefit from the use of a daily multivitamin, individuals most likely to benefit include women who might become pregnant, persons who regularly consume 1-2 alcoholic drinks per day, the elderly, vegans, and poor urban residents who do not eat a healthy diet (Willett & Stampfer, 2001).
What does the RDA or DRI tell you?
The Recommended Dietary Allowance (RDA) provides information about the appropriate level of a nutrient that meets the needs of practically all healthy individuals in the general population (Bland et al., 1999). In general, the RDA tends to err on the side of being low in order to meet 100% of the government standards (Bland et al., 1999). The Dietary Recommended Intakes (DRI) were established to provide additional information, such as upper limits and recommendations for adequate intakes when there is insufficient data to determine the RDA (Mertz, 2000). The study of required intakes is complicated by variations in levels of consumption of natural food sources, variations in nutrient content of the same foods, and nutrient interactions (Mertz, 2000; Willett & Stampfer, 2001). Thus, lack of data has required RDA and DRI committees to use a significant amount of judgment in choosing between a range of intakes (Mertz, 2000). Furthermore, since the RDA and DRI recommendations establish levels for the general population, they do not account for differences in individual biochemical requirements, nor do they establish optimal intake for individuals experiencing an illness or environmental stressors (Bland et al., 1999).
How much of a supplement should you take?
Information provided by the RDA and DRI levels can provide a starting point, but are inadequate for therapeutic doses or levels required to ameliorate symptoms. Depending your your medical history and other complicating factors such as your diet, I will work with you to determine (and subsequently adjust) your individual optimal daily dose, which will also change over time. For your information, we have provided a list of vitamins and minerals summarized by individual vitamins and minerals, including physiologic functions of the nutrient, selected natural food sources, adverse effects of severe deficiency, potential therapeutic uses of increased intake, and toxic effects of excess intake. It is hoped that the reader will use this information to consider the use of a particular nutrient. To determine your individual needs more specifically, we can discuss your needs during your next follow up visit. Also remember that our office offers specialty testing for nutritional deficiencies, immune surveillance, or other conditions that may alter the recommended supplement intake for you. This information is for education use only and does not subsitute for the supervision of a physician. Please do not start or stop any current medications without the advise from a physician.
Also included is information about the preferred form of a nutrient that will increase its bioavailability, as well as a proposed scheduled for taking the supplements. The schedule accounts for the various interactions between nutrients. For example, calcium blocks the ability to absorb zinc, iron and copper (Galland & Buchman, 1988). Zinc and iron interfere with each other’s absorption (Galland & Buchman, 1988). Phosphorous interferes with calcium absorption (Bland et al., 1999). For practical purposes, you may want to buy a multivitamin that ignores these and other interactions. However, using this information to consider the optimal timing of intake as well as most bioavailable form, you may buy additional supplements to meet your individual needs. For example, a woman may buy a multivitamin that she takes in the morning, but buy an additional bioavailable form of calcium to take in the evening.