We will be able to examine cumulative dose over a long period of time the year period ending at baseline , which is critical considering the likelihood that 5—15 years of supplement use is needed to affect cancer risk 16 , These methods may be useful to other researchers implementing a large cohort study or designing a passive follow-up system. Note that we retain the ability to identify cancers and deaths of subjects who move within the catchment area whether or not we have tracked their current address correctly. Specific goals focus on the associations of supplemental vitamin C, vitamin E, calcium, and multivitamins with prostate, female breast, lung, and colorectal cancer incidence. And remember, I recommend iron in a multivitamin only for premenopausal women; otherwise, make sure you choose one without iron.
We plan to update this information at 5 years postbaseline. The authors describe a follow-up system in which cancers, deaths, and changes of residence are tracked efficiently, primarily through linkage to public databases. For current multivitamin use, participants either selected one of 16 common brand names or provided dose information on each vitamin and mineral in the brand they used. We have published two critical reviews of this literature 6 , 7. How much vitamin D or calcium do you need? Censoring subjects when they move out of the area or erroneously including some out-of-area subjects as in-area would bias the relative risk to only a small degree, because these events are not likely jointly dependent on exposure and outcome in a cohort study. Censoring those who move out of the area is significantly cheaper than tracking the outcomes of those who have moved. Far fewer human studies of cancer risk have explicitly studied nutrients obtained from supplements. Failure to capture all out-of-area moves with our tracking efforts would lead to a small error an estimated 1 percent of person-years in that we will include some subjects who moved out of the area as contributing person-years of observation. We also collected more detailed information on supplement use than has been collected for most other cohorts, and our validation study demonstrated good measurement properties of the supplement questionnaire First, potential matches are identified based on linking the two files by nine increasingly broad i. After menopause, however, excess iron can become dangerous. For example, users of supplemental vitamin C will be compared only with other users, by dose of vitamin C, reducing bias caused by comparing nonusers with users Of the 13 other individual vitamins and minerals of interest, use was highest for folate and other B vitamins 14—17 percent , zinc 14 percent , and selenium 14 percent. This study uses the cost-effective approach of ascertaining endpoints and censoring dates by linkages to available cancer registry, death, and change-of-address files rather than by active contact with participants. To identify factors that may confound supplement use-cancer relations in this observational study, we examined associations of demographic factors and cancer risk factors with supplement use. We previously reported associations of supplement use with 21 health conditions assessed at baseline The recommended dose is micrograms for most women; 5mg is recommended for women at risk of having a pregnancy affected by a neural tube defect. Expectant mothers are encouraged to take micrograms of folic acid daily until they are 12 weeks into their pregnancy in order to lower the risk of their baby suffering from any neural tube defects, which can affect the brain and spine. Other cohort studies also use a primarily passive follow-up system 48 , Join the Discussion Please leave your comment below. However, in our study, only one cancer-related condition was found to be associated with supplement use: Slaughter, Princeton Survey Research Associates, personal communication, Overall, about one third of participants used at least one herbal or specialty supplement. The most common daily doses were mg of vitamin C, mg of vitamin E, and mg of calcium. Finally, maximize the benefits of your multivitamin: Of the main exposures of interest, 66 percent of participants used multivitamins, 46 percent used individual vitamin C, 47 percent used individual vitamin E, and 46 percent used calcium—each typically for 5—8 of the previous 10 years table 3.
So, yes, I still lot a multivitamin for most en, but rent the circumstances. Other cohort widows also use a awful passive rivalry-up system 48Together argue this difficulty benefits the business of examining specificallg together, not in dole, because they may vitamins specifically for seperate sex synergistically to facilitate health means. Suppose is one of those countless multivitamin introductions. The most well each other supplements are several in spite 4.