Research reveals that fortified food and supplement users had better nutrient intake profile

Japanese adults who consumed fortified foods, supplements or both had a higher intake of vitamins and minerals than non-users when nutrient intake was not considered from these “health foods,” according to a new study. Adults had a higher intake of fiber, vitamins, minerals, fruits, fish and seafood, and dairy products from their base diet.

Among fortified foods and supplement users, these products contributed to the adequate intake of thiamine, riboflavin, vitamin B6, vitamin C and calcium. A higher share of this group met the proper intake levels set by dietary reference standards. 

At the same time, the researchers cautioned that there was a risk of exceeding the tolerable upper intake level (UL) of vitamin B6 among users, as 2% of users exceeded it. 

“These results can be used to design strategies for improving micronutrient intake in Japan and could be the foundation for future research with more nationally representative samples,” note the authors.

Nutrient intake levels

For the study, published in BMC Nutrition, researchers from Toho University, Japan, analyzed the dietary intake of 392 Japanese adults aged 20–69. The team estimated nutrient intake from four-day dietary records, considering intakes from base diets and total intake — base diets plus fortified food and dietary supplement intake. 

The researchers defined “users” as participants who consumed at least one fortified food or supplement during the recording period, amounting to 122 users. Fortified foods contributed 4% to this group’s total food intake, and supplements 21%. 

In the study, 10% of the participants consumed fortified foods, 24% used supplements and 31% consumed either product. Users of these products were older than non-users, but there was no difference in the distribution of sex or educational level. 

The team also calculated the share of participants whose intake was below the estimated average requirements or exceeded the ULs provided in the Dietary Reference Intakes in  Japan. The researchers assessed adequate intake of 14 nutrients — protein, vitamins A, B6, B12 and C, thiamin, riboflavin, niacin, folate, calcium, magnesium, iron, zinc and copper. 

The researchers note that study participants’ health-consciousness may impact their high nutrient intake from base diets.Users were more likely to meet estimated average requirements for six nutrients from their base diets (vitamins A and B6, thiamine, riboflavin, calcium and zinc) and three additional nutrients in their total intake (vitamin C, magnesium and iron). 

Fortified foods and supplements helped increase the adequate consumption levels of thiamine, riboflavin, vitamin B6, vitamin C and calcium.

However, the researchers caution that even when considering fortified food and supplement intake, over 30% of participants consumed inadequate vitamin A, calcium, magnesium and iron levels.  

Several companies and researchers aim to overcome global micronutrient deficiencies. For example, dsm-firmenich unveiled a dry vitamin A to fortify flour. Meanwhile, researchers suggest adding beans and pulses to the diet to address shortfalls in iron, zinc, magnesium, calcium and fiber.

Follow-up research

The researchers also indicate several limitations in their study, such as the short dietary record of four days. The team did not identify the use of fortified foods if participants did not record a food’s brand name. Moreover, some participants may not have recorded their supplement use since the study aimed to identify sodium and potassium intake. 

The study had a small, non-random sample, with all participants working at welfare facilities. The researchers caution that the group may have been health conscious, which could have impacted the results. 

As the study took place in winter, the researchers suggest there may have been seasonal effects on food choice. They also note that the estimate of nutrient intake “is prone to misreporting” due to changes in dietary habits over the assessment period. 

“Although significant differences in nutrient intake were observed between users and non-users, further studies with large sample sizes are required,” conclude the authors.