Background: γ-Tocopherol is the most abundant form of vitamin E in the US diet, but α-tocopherol concentrations are the highest in plasma and tissues. Although plasma and adipose tissue concentrations of α-tocopherol have been used as biomarkers of intake, the relation between γ-tocopherol intake and concentrations in plasma and adipose tissue is unknown.

Objective: Our goal was to investigate in a randomly selected population from Costa Rica whether plasma or adipose tissue concentrations of α- and γ-tocopherol are suitable biomarkers of intake.

Design: A total of 361 men (x̄ ± SD age: 55 ± 11 y) and 121 women (aged 59 ± 10 y) completed a 135-item food-frequency questionnaire and provided a fasting blood sample and adipose tissue biopsy sample.

Results: Dietary γ-tocopherol correlated with adipose tissue (r = 0.37, P < 0.001) and plasma (r = 0.42, P < 0.001) concentrations, regardless of supplement use. Dietary α-tocopherol correlated poorly with adipose tissue (r = 0.15, P < 0.01) and plasma (r = 0.16, P < 0.001) concentrations, and these correlations were even lower when users of vitamin supplements (n = 24) were excluded (adipose tissue: r = 0.10, P < 0.05; plasma: r = 0.09, P < 0.05). Compared with subjects who reported palm shortening (36%) as the major type of fat used for cooking, subjects using soybean oil (52%) had higher amounts of both α- and γ-tocopherol in their diets. However, only γ-tocopherol concentrations were higher in the plasma and adipose tissue of soybean oil users.

Conclusions: Plasma and adipose tissue concentrations of γ-tocopherol are equally good biomarkers of intake. The weak associations between α-tocopherol intake and plasma or adipose tissue concentrations suggest that these biomarkers are influenced more by factors other than α-tocopherol intake.