Abstract
Background: Riboflavin is an important B-vitamin for a range of metabolic and antioxidant processes within the body. Adolescent females are particularly at risk of inadequate riboflavin intake due to traditionally poor dietary habits and increased requirements for growth. The most recent evidence investigating riboflavin intakes and food sources of riboflavin in New Zealand adolescent females is now a decade old. Since then, transformation of the food supply, such as an increase in processed foods, and changes in dietary patterns, with a shift towards more plant-based diets, may have impacted nutritional intake. In particular, milk and animal-based foods, which are naturally high in riboflavin, are typically the largest dietary contributors of total riboflavin intake in healthy population groups. The impact of these potential changes on riboflavin intakes of New Zealanders is unknown.
Objective: To determine the prevalence of adequate riboflavin intake and the major food groups contributing to riboflavin intake among 15-18 year-old females in New Zealand.
Design: This study was a cross-sectional survey of 145 females aged 15-18 years, attending seven secondary schools across New Zealand. Socio-demographics, dietary habits, attitudes and food choice motivation were collected via an online questionnaire.
Weight and height were collected using standardised techniques and body mass index (BMI) z-scores were calculating using the World Health Organisation BMI-for-age Growth References for 5-19 year-old females. Dietary intakes were assessed via two interviewer-led 24-hour recalls, and usual daily intake of energy and riboflavin were adjusted for intra-individual variation using Multiple Source Methods. Prevalence of inadequate riboflavin intake was estimated using the estimated average requirement (EAR) cut-point method. The top ten food sources of riboflavin were determined using the population ratio approach.
Results: The overall intakes of riboflavin in the population were fairly adequate, with a prevalence of inadequate intake of 9.1%. The mean and median riboflavin intakes were 1.60 mg/day and 1.50 mg/day, respectively. Milk was the greatest dietary contributor of riboflavin intakes in the study population, albeit was consumed by only 61.4% of participants. Other top ten contributors to riboflavin intake ranked highest to lowest were: breakfast cereals, bread-based dishes, vegetables, grains and pasta, savoury sauces and condiments, poultry, dairy products, bread and fruits. Participants who reported regular consumption of milk (cow’s and other milks), eggs, other dairy, red meat, poultry and fish had significantly greater intakes of riboflavin than participants who consumed these foods irregularly. However, foods high in riboflavin such as milk and meat were consumed less than foods less dense in riboflavin such as vegetables, bread and fruit.
Conclusion: While the overall prevalence of inadequate riboflavin intake in the present study was low, findings suggest that those who reported irregular consumption of meat and milk may be at particular risk of inadequate intake. This is particularly relevant to vegetarians (avoidance of meat and/or eggs), and even more so to vegans (avoidance of all animal products). Findings from the study also highlighted certain socio-demographic groups who may be at increased risk of inadequate intakes however small sample sizes limited interpretation and further recruitment is needed to ascertain whether concern is warranted.