The level of usage of dietary supplements reported by physicians in this survey is similar to the level of usage reported in some surveys of the general population. However, it should be noted that the reported level of usage in the general population is not consistent across surveys, in part because the exact nature of the question asked varies among surveys. Some surveys inquire about use within a short period of time such as the past two weeks or month, some ask about use within the past year, and some pose a general question about supplement use without specifying a time period. The first of these approaches will capture primarily regular users as well as some occasional users, while the last approach will capture virtually all supplement users. Some surveys inquire only about vitamin/mineral supplement use and some cover a broader range of dietary supplements.
The HCP Impact Study asked whether respondents took dietary supplements regularly, occasionally, seasonally, in the past, or never. The question was not limited to vitamin/mineral supplements, but included all types of dietary supplements. The prevalence of regular dietary supplement use reported by dermatologists and orthopedists in this survey (59% and 50%, respectively) was similar to the prevalence of use reported among adults in NHANES 1999-2000 and NHANES 2003-2006, where 52% and 54% of adults surveyed said they had taken supplements in the past month [1, 2]. In the NHANES 1999-2000 study, the prevalence of supplement usage was higher in subgroups of adults more nearly comparable to the physicians in the HCP Impact Study, in terms of age and education: usage was 56% among adults in the 40-to-60 age range and 62% among adults with more than a high school education. NHANES 2003-2006 and NHIS 2000 also reported increased levels of supplement use in adults with more education and in older adults compared to young adults, although different age groupings were used [2, 3]. In the HCP Impact Study, the prevalence of regular dietary supplement use by cardiologists was only 37% -- lower than for the other physician specialists and lower than for the general population in recent NHANES reports.
The proportion of physicians in the HCP Impact Study who reported any supplement use is relatively high, since this figure includes seasonal or occasional use, as well as regular use. Our total usage figure was 75% for dermatologists and 73% for orthopedists, while total usage for cardiologists was lower at 57%. For comparison, a survey of a large multiethnic cohort reported that 58% of men and 72% of women used any of eight dietary supplements regularly (at least once a week) . It should be noted, however, that the multiethnic survey included as supplement users only those who used one of the defined eight product types at least once a week and therefore did not include seasonal or occasional users and did not include users of products other than the eight specified.
A series of consumer surveys conducted for the Council for Responsible Nutrition also provide information about dietary supplement use in the general population. In a survey of about 2000 individuals in 2009, 65% of respondents identified themselves as dietary supplement users (regular, occasional, or seasonal). This figure has been very consistent in surveys conducted by CRN over the past several years: 64% in 2008, 68% in 2007, and 66% in 2006 .
Other surveys of dietary supplement use among health professionals have reported substantial levels of usage, from 64% to over 80%. In a survey of women physicians, it was reported that 64% used vitamin or mineral supplements at least occasionally, and 47% of the women used a vitamin or mineral supplement at least 5 days a week . Two surveys of health professionals enrolled in an online course on dietary supplements reported high levels of supplement use (over 80%), perhaps reflecting the interest that led them to enroll in the course [19, 20].
We have previously reported the results of an earlier survey of dietary supplement use by physicians and nurses . In that survey, 72% of the physicians and 89% of the nurses said they used dietary supplements at least occasionally, while 51% of the physicians and 59% of the nurses said they were regular supplement users. The current results for dermatologists and orthopedists are similar to our earlier findings for other physicians, but reported usage by cardiologists in the current survey is lower.
The use of dietary supplements can be viewed as one of several elements of a healthy lifestyle, since the use of dietary supplements is associated with the adoption of other healthy habits, including control of body weight, engaging in moderate or vigorous physical activity, and not smoking . The vast majority of the physicians included in this survey said they tried to eat a balanced diet (80% of cardiologists, 81% of dermatologists, and 77% of orthopedists), maintain a healthy weight (69%, 79%, and 69%, respectively), and exercise regularly (67%, 70%, and 69%, respectively).
It is interesting that the reasons given for using dietary supplements and the reasons given for recommending dietary supplements to patients were not the same. Maintaining wellness was the top reason for personal use, but reasons relating to specific health issues were the top reasons for patient recommendations, and the health issues were related to the specialty of the physicians. This is consistent with the fact that the type of supplement most commonly used by physicians is a multivitamin, while the supplements they discuss most with their patients reflect their specialty. This is not surprising, since their patients are people who have come to a medical specialist, presumably with a specific problem, and the physicians make recommendations for medications, interventions, or possibly dietary supplements within their field of expertise. Cardiologists were more likely to say they made recommendations related to heart health and cholesterol; dermatologists, to the condition of the skin, hair and nails; and orthopedists, to bone and joint health or musculoskeletal pain.
Although majorities of physicians included in our survey reported using and recommending supplements, they clearly were also aware of potential concerns, as indicated by their interest in continuing education regarding issues such as interactions with pharmaceuticals. There has been a longstanding concern that medical education fails to provide practitioners with a sound basis for evaluating the role of nutrition in health and disease . Providing more nutrition education in medical schools and increasing the availability of Continuing Medical Education relating to nutrition, including discussion of the role of dietary supplements, would be beneficial for physicians as well as for their patients.