The research team, led by Sarah L. H. Kamhout of the Department of Psychology at Brigham Young University, recruited 80 adolescents between the ages of 14 and 18 from the general community. Participants completed detailed 24-hour dietary recalls using the National Cancer Institute’s Automated Self-Administered 24-hour dietary assessment tool, known as ASA-24, on two to three randomly assigned days that included both weekdays and weekends. The tool captured intake of 26 different micronutrients, ranging from familiar players like calcium, iron, and vitamin D to less-studied carotenoids such as lycopene, lutein, and zeaxanthin. Participants were notified of their assigned recall day only on the day itself, a design choice intended to prevent them from altering their eating habits in response to being observed.

Sleep was measured with unusual rigor for a study of this kind. Each participant wore a wrist-worn actigraph for 7 to 20 days, providing objective data on sleep onset time, sleep midpoint, total sleep duration, sleep efficiency, and wake after sleep onset, a measure known as WASO. Because adolescents are known to be unreliable reporters of their own sleep habits, actigraphy readings were cross-verified with daily sleep diaries. The Sadeh algorithm, a validated method for converting movement data into sleep-wake states, was used to score each night. Sleep efficiency was calculated as the ratio of time asleep to time in bed, and all time-based variables were converted to minutes after midnight to avoid circular calculations.

Beyond nightly sleep, the study also probed more trait-like dimensions of sleep health. Participants completed the Morningness-Eveningness Questionnaire to assess chronotype, their innate preference for early or late sleep and wake times, and the Epworth Sleepiness Scale for Children and Adolescents to gauge daytime sleepiness. Most notably, each subject underwent a six-hour dim light melatonin onset protocol, or DLMO, in the laboratory. After a three-to-five-day at-home sleep stabilization period, saliva samples were collected every 30 to 45 minutes under light levels below 5 lux, beginning five hours before and ending one hour after each participant’s preferred bedtime. DLMO was defined as the moment salivary melatonin concentrations exceeded 4 picograms per milliliter, a threshold previously validated in adolescents. The gap between DLMO and average sleep onset, called the phase angle, served as a measure of circadian alignment, with values between two and four hours considered clinically aligned.

The statistical approach was equally careful. Because dietary reference intakes differ between males and females due to distinct biological and metabolic needs, all analyses were performed separately by sex. The researchers used mixed effects models with random by-participant intercepts to account for multiple dietary intakes per participant, then applied backwards step-wise model fitting to remove micronutrients that did not improve overall model fit. Variance inflation factors below five confirmed low collinearity in all final models, and p-values were corrected for multiple comparisons using the Benjamini-Hochberg false discovery rate procedure, applied separately for daily and averaged models.

Against the researchers’ initial hypotheses, no single micronutrient emerged as significantly associated with improved sleep health across all models. Yet two nutrients showed the most consistent positive signals. Potassium, with coefficients ranging from -0.03 to 0.004 and p-values below 0.05, was linked to increased same-night sleep efficiency in both males and females, and to earlier sleep onset in females. Retinol, a specific chemical form of vitamin A, showed associations with better sleep efficiency in females and earlier sleep midpoint and onset in males, with coefficients ranging from -0.20 to 0.01 and p-values below 0.05. These findings echo a classic double-blind, placebo-controlled crossover study in nine adult males on potassium-deficient diets, where supplementation improved sleep efficiency and consolidation, and more recent work linking lower urinary potassium excretion to greater daytime sleepiness in adults.

On the other side of the ledger, zinc and vitamin B12 were the micronutrients most consistently linked with negative sleep outcomes. Zinc, with coefficients ranging from -0.54 to 3.51 and p-values below 0.10, was associated with later sleep onset in males on the same night, reduced average sleep efficiency in males, and increased daytime sleepiness in both sexes. Vitamin B12, with coefficients ranging from -0.96 to 7.22 and p-values below 0.05, was linked to later sleep midpoint in males, reduced sleep efficiency in females, and increased wake after sleep onset in males. Notably, mean vitamin B12 intake in the sample surpassed the recommended daily allowance roughly three-fold for males and five-fold for females, a pattern consistent with prior research suggesting vitamin B12 can have an alerting effect that delays sleep onset and shortens sleep duration.

The dietary data itself revealed a troubling picture of adolescent nutrition. Less than 2 percent of youth ages 14 to 18 meet recommended vegetable intake guidelines according to national survey data, and only 2.9 percent of children and adolescents meet daily whole grain requirements. In this sample, average intake of sodium, copper, selenium, vitamin C, niacin, vitamin B6, vitamin K, and vitamin B12 exceeded recommended daily intake ranges for both sexes, while average intake of calcium, magnesium, potassium, vitamin D, and vitamin A fell below recommended ranges. Over half of participants did not meet recommended vitamin D intake, a deficiency consistently associated with decreased sleep duration and poorer sleep efficiency in children and adolescents. Iron, frequently tied to sleep disorders such as restless legs syndrome in prior research, showed no significant associations in this study, possibly because the female sample was on average below the recommended daily allowance for iron, making it difficult to detect effects of adequate or excess consumption.

The researchers emphasize that their findings are exploratory signals rather than established causal relationships. The cross-sectional design limits causal inference, though the day-to-night matching of dietary intake with same-night sleep helps establish temporal precedence in some analyses. Self-reported dietary recalls introduce potential recall and desirability biases, and the ASA-24, while demonstrating strong agreement with interviewer-administered recalls, is not a perfect measure of true intake. Absorption and metabolism of micronutrients also vary by individual, influenced by storage levels, interactions between nutrients, and whether intake comes from food or supplements. Carotenoids, for instance, are absorbed less efficiently than retinol, and people with low stores of vitamins A, calcium, and iron increase their ability to absorb more of these nutrients, meaning individual adolescents may have exhibited different patterns of absorption related to their specific consumption patterns.

Despite these limitations, the study represents the first broad examination of micronutrient intake and sleep health in adolescents, a population where nearly 70 percent fail to obtain the recommended 8 to 10 hours of sleep and over 40 percent report sleeping less than 7 hours per night. The findings suggest that sleep may be sensitive to day-to-day shifts in potassium intake, that different chemical forms of vitamin A may play distinct roles in sleep timing, and that zinc and vitamin B12 warrant closer scrutiny for their potential negative associations with sleep during adolescence. The researchers call for experimental and longitudinal designs to clarify causal pathways and for interventions tailored to individual intake patterns, timing of consumption, and interactions between multiple nutrients. No universal, one-size-fits-all dietary solution for improving adolescent sleep emerged from this work, but the study opens a promising avenue for understanding how the food on a teenager’s plate might ripple through the architecture of their night.

Subject of Research: Nutrition and Sleep Science

Article Title: In search of vitamin sleep: cross-sectional analysis of vitamin and mineral intake and sleep health outcomes in adolescents

Article References: Kamhout, S. L. H., Bellini, S. G., Luke, S. G., Homer, K. J., Broadbent, M., & Duraccio, K. M. (2026). In search of vitamin sleep: cross-sectional analysis of vitamin and mineral intake and sleep health outcomes in adolescents. Frontiers in Nutrition, 13, Article 1978612. https://doi.org/10.3389/fnut.2026.1978612

Image Credits: AI Generated

DOI: 10.3389/fnut.2026.1978612

Keywords: adolescent sleep, micronutrients, potassium, retinol, zinc, vitamin B12, circadian rhythm, DLMO, actigraphy, sleep health, search, vitamin