Nutrient Intake from Voluntary Fortified Foods and Dietary Supplements in Japanese Consumers: A Cross-Sectional Online Survey

Contribution of fortified foods and dietary supplements to total nutrient intakes and their adequacy in Japanese adults

BACKGROUND

This study examined how fortified foods and dietary supplements contributed to total nutrient intakes and their adequacy in Japanese adults.

METHODS

Nutrient intake was estimated from 4-day dietary records of 392 adults (20-69 years) in total intake considering intakes from fortified foods and dietary supplements and in base diets without considering their intake. Users were defined as participants who used at least one fortified foods and/or dietary supplements during the 4-day recording period. The proportion of participants whose intake was below the Estimated Average Requirements (EAR) or exceeded the Tolerable Upper Intake Level (UL) provided in the Dietary Reference Intakes for Japanese was calculated.

RESULTS

In 122 identified users (31% of participants) of fortified foods and/or dietary supplements, the mean contributions of fortified foods and dietary supplements to total intake were < 4% and < 21%, respectively, for all 25 examined nutrients. Users were more likely to meet the EAR than non-users for six nutrients in the base diets and nine nutrients in the total intake. Among the users, the prevalence of participants below the EAR decreased by ≥ 10% in the total intake compared with the base diet for five nutrients. No nutrient intake from the base diet exceeded the UL in users and non-users; however, vitamin B6 intake in 2% of users exceeded the UL of their total intake.

CONCLUSION

Although the users of fortified foods and/or dietary supplements had better nutrient intake than non-users in base diets, fortified foods and dietary supplements helped the Japanese users achieve adequate intakes of certain nutrients without a risk of excessive intake (except for vitamin B6).

Usual Nutrient Intake Distribution and Prevalence of Nutrient Intake Inadequacy among Japanese Children and Adults: A Nationwide Study Based on 8-Day Dietary Records

In this cross-sectional study, we evaluated nutrient intake adequacy in 4450 Japanese people aged 1-79 years. Dietary data was collected through non-consecutive 8-day weighed dietary records. Usual nutrient intakes from foods and beverages were estimated using the Multiple Source Method. Participant proportions with intakes below and above the Japanese Dietary Reference Intakes (2020) were calculated. Usual intakes of most nutrients were below the Estimated Average Requirement; calcium showed a high percentage of inadequacy across all sex and age groups (29-88%), and iron showed a high inadequacy among females aged 12-64 years (79-95%). The percentages of energy from protein and carbohydrates, dietary fibre, and potassium were typically below the lower limit of the Tentative Dietary Goal for Preventing Lifestyle-related Diseases (DG). Furthermore, over 20% of the participants exceeded the upper limit of the DG for the percentages of energy from total and saturated fats, and over 88% exceeded the upper limit of the DG for sodium. Japanese children and adults could improve their nutrient intake by increasing calcium, iron, dietary fibre, and potassium and reducing total and saturated fats and sodium. These findings can inform policies and interventions to improve nutrient intake in Japan.