Use of Dietary Supplements among Japanese Female Nursing Professionals

The use of dietary supplements has become a common way to maintain good health. This study evaluated the status of supplement use and supplement user characteristics among participants from the Japan Nurses' Health Study, which comprised a cohort of Japanese female nursing professionals. A questionnaire survey covering the use of vitamins and supplements was conducted. Supplements were classified according to their constituents and formulations. Logistic regression analyses were performed to determine the characteristics of supplement users. Results were as follows. There were 4,017 supplement users (34.4% of 11,665 valid answers). The supplement types used were: vitamins (n=2,655), minerals (n=1,121), amino acids and proteins (n=139), botanical products (n=714), animal by-products (n=849), herbal medicines (n=152), nutritional drinks (n=19), others (n=117), and unclassified supplements (n=320). Logistic regression analyses showed that supplement use was significantly associated with age and body mass index, and there were significantly higher proportions of supplement users among pregnant women, black tea drinkers, soy milk consumers, and lactobacillus beverage drinkers. In conclusion, the overall percentage of supplement users was 34.4%. A high prevalence of supplement use was observed among older, non-obese, and pregnant participants, and those who paid more attention to their health. The prevalence of supplement users was significantly higher among those who habitually drank black tea, soy milk, and lactobacillus beverages, suggesting participants used supplements to maintain their health or prevent diseases based on high health consciousness.