Nutritional status is the balance between intake and expenditure, the assessment of which is highly complex and individualized. Dietary supplements can be beneficial for covering the shortcomings of some people’s diets, but must not be used to replace the balanced variety of foods necessary for a healthy diet.
 In Japan, the term “supplement” is used without a clear legal definition. Many supplements contain active ingredients that may have strong and unpredictable detrimental biological effects on the human body. Some dangerous products may carry illegal health claims or contain pharmaceutical ingredients with a high risk of adverse effects. When using dietary supplements, it is important to consider their necessity and efficacy, and to obtain the advice of health-care professionals who have sufficient knowledge about nutrition.
 Our anti-aging health check-up provides personal nutrition advice based on serum vitamin levels and detailed information about dietary habits. To help people make informed decisions, the doctors and dietitians work together to decide how people can achieve a balance between the foods and nutrients they personally need. We do not always find that people need supplements, and sometimes we find those who use supplements inappropriately.
 This article presents a current overview of dietary supplements in Japan and our approach to providing supplement advice in our anti-aging health check-up system, and gives a helpful perspective in evaluating and promoting good health.