Ethnic differences in thiamine status persist after adjusting for diet; findings from the UK National Diet and Nutrition Survey

BACKGROUND/OBJECTIVES: Thiamine (vitamin B1) status might play a role in cognition and mental health. Recent research suggests that there are ethnic differences in thiamine status. We aimed to test the hypothesis that black individuals have a higher risk of thiamine deficiency than white individuals, based on the erythrocyte transketolase activity coefficient (ETKAC), and assess differences in thiamine intake, using nutritional survey data. METHODS: We used the published data of the UK's National Diet and Nutrition Survey Rolling programme (2008-2019) and examined differences in the ETKAC between ethnicities and risk of thiamine deficiency (ETKAC >1.25). We also used dietary data to determine differences in thiamine intake between ethnic groups. RESULTS: Within the NDNS 2008-2019 ETKAC measurements were available for 5657 participants (5170 white, 92 black, 228 Asian, 93 mixed and 74 other ethnic groups). The median ETKAC of black participants was higher (1.15 (0.08) median (IQR)) than white (1.10 (0.07)) or Asian (1.12 (0.08)), indicating poorer thiamine status among black participants. The prevalence of thiamine deficiency was 5 % among black participants, being greater than among white (0.5 %) and Asian participants (1.3 %). This was independent of age, sex, body composition and socio-economic status. Dietary assessment data suggested that thiamine intake was on average lower for black participants compared to white or Asian participants Including dietary intake into the model was not sufficient to correct for the ethnic difference in thiamine status. CONCLUSIONS: This study suggests that there are ethnic differences in thiamine status that cannot be readily explained by intake alone.