# L-shaped relationship between dietary vitamin E intake and migraine in adults: a cross-sectional analysis of NHANES 1999–2004

## TL;DR

This study found that higher vitamin E intake is linked to lower migraine risk in adults, but only up to a point of 7.3 mg/day.

## Contribution

The study reveals a nonlinear, L-shaped relationship between dietary vitamin E and migraine risk with a specific inflection point.

## Key findings

- An L-shaped nonlinear association exists between dietary vitamin E and migraine (p = 0.006).
- The inflection point for vitamin E intake and migraine risk is at 7.3 mg/day.
- Vitamin E intake above 7.3 mg/day does not further reduce migraine risk.

## Abstract

Several previous studies have suggested that micronutrients with antioxidant properties are protective factors against migraine. Despite being an important dietary antioxidant, the relationship between dietary vitamin E and migraine has not been extensively studied. This study sought to understand the association between dietary vitamin E intake and the incidence of migraine.

Data from the National Health and Nutrition Examination Survey (1999–2004) were used in this cross-sectional analysis. To assess the association between dietary vitamin E intake and migraine, we employed logistic regression, restricted cubic spline regression, and stratified analyses.

This study included 10,063 participants who were 20 years old or older, 20.1% (2018/10,063) of whom reported suffering from migraine. Compared with the lowest vitamin E intake T1 (<4.5 mg/day), the adjusted odds ratios (ORs) of dietary vitamin E intake and migraine for T2 (4.5–7.8 mg/day) and T3 (>7.8 mg/day) were 0.85 (95% confidence interval [CI]: 0.74–0.98, p = 0.03) and 0.75 (95% confidence interval [CI]: 0.63–0.90, p = 0.001), respectively. An L-shaped nonlinear association existed between dietary vitamin E consumption and migraines (p = 0.006). For participants who consumed <7.3 mg of vitamin E daily, the OR for migraine was 0.92 (95% CI: 0.874–0.969, p = 0.0015). When daily vitamin E intake was ≥7.3 mg/day, the risk of migraine did not continue to decrease with increasing dietary vitamin E consumption (OR, 1.008; 95% CI, 0.984–1.033). The results of the sensitivity analysis suggest that the association between dietary vitamin E intake and migraine remains robust.

In adults, the association between dietary vitamin E intake and migraine is an L-shaped curve (nonlinear, p = 0.006), with an inflection point at 7.3 mg/day. It reminds individuals to keep diets balanced.