Although many validation studies of FFQ have been reported, only a few addressed the effect of inclusion of dietary supplement use on the validity of micronutrient estimates. The purpose of the present study was to assess reproducibility and validity of a self-administered FFQ, intended to measure total nutrient intake from diet and from dietary supplements, in a random population-based sample of 248 middle-aged and elderly men (40-74 y old) in central Sweden. Fourteen 24-h recall interviews were used as the reference method. Participants were telephoned about once a month for 1 y, covering every day of the week, twice in random order. Spearman correlation coefficients increased 13% (from 0.49 to 0.62), between FFQ-based micronutrient estimates and the fourteen 24-h recall interviews (reference method) when supplement use was included. Correct classification into highest quintiles was also improved by 14% (from 37 to 51%). There were no differences in mean intraclass correlation coefficients for 1-y reproducibility between total micronutrient intake and micronutrients from foods only. The increase in the validity of micronutrient estimates due to inclusion of supplements in nutrient intake assessment has important implications for sample size in epidemiologic studies. Because a dramatic increase in dietary supplement use has occurred in recent decades in many countries, the issue of including supplements in dietary assessment should be of highest priority in nutritional epidemiologic studies of chronic diseases.

Objective: To investigate which subgroups of the Swedish adult population use dietary supplements and natural remedies, taking into account sociodemographic and health behaviour factors. Design: A cross-sectional survey conducted in 1996=1997 by Statistics Sweden was used for the analyses. In faceto-face interviews participants reported consumption of dietary supplements and natural remedies during the previous 2 weeks. Setting: Sweden Subjects: A nationally representative sample of 11 422 adults (5596 men, 5826 women) aged 16 -84 y. The response rate was 78%. Results: Overall, 33% of Swedish women and 22% of Swedish men reported use of dietary supplements; prevalence of natural remedy users was 14 and 7%, respectively. The best predictors for use of dietary supplements and natural remedies were age, sex and subjective health. Women and older individuals were more likely to be dietary supplement and=or natural remedy users. Obese men and women were less likely to use dietary supplements than underweight ones. Among men subjective health was significantly related to use of these preparations. Men who reported excellent health ate less than men reporting poor health. This association was weaker among women. Exercise was another important factor. Both men and women (except female dietary supplement users) who reported moderate or heavy exercise were significantly more frequent users of these preparations than those who reported practically no exercise. Conclusion: Use of dietary supplements and natural remedies is associated with several sociodemographic and health behaviour factors.

These findings suggest that promoting MVPA may be have a beneficial effect on attention capacity, an important component of cognition, in adolescents.

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The use of dietary supplements has increased substantially in most industrialized countries. The aim of this study was to prospectively examine the association between use of dietary supplements and all-cause mortality, cancer mortality and CVD mortality in men. We used the population-based prospective cohort of 38 994 men from central Sweden, 45 -79 years of age, with no cancer or CVD at baseline and who completed a self-administered FFQ including questions on dietary supplement use and life-style factors in 1997. During average 7.7 years of follow-up, 3403 deaths were ascertained; among them, 771 due to cancer and 930 due to CVD (during 5.9 years of follow-up). In multivariate adjusted models including all men there was no association observed between use of any dietary supplement or of multivitamins, vitamin C, vitamin E or fish oil specifically and all-cause mortality, cancer or CVD mortality. Among current smokers, regular use of any supplement was associated with statistically significant increased risk of cancer mortality: relative risk (RR) 1·46 (95 % CI 1·06, 1·99). Among men reporting an inadequate diet at baseline (assessed by Recommended Food Score), there was a statistically significant inverse association between use of any dietary supplement and CVD mortality (RR 0·72; 95 % CI 0·57, 0·91), no associations were observed among men with adequate diets. In conclusion, we cannot exclude that the use of dietary supplements is harmful for smokers. On the other hand, among men with an insufficient diet, the use of supplements might be beneficial in reducing CVD mortality.