Prevalent low Mediterranean diet adherence and low folate status in a Spanish Km 0 Mediterranean coast population

Background Folate, vitamin B 12 , riboflavin, and vitamin B 6 , play interrelated roles in one-carbon metabolism, vital for several physiological processes. Objective To assess intake and status of these B-vitamins in an adult Mediterranean population unexposed to mandatory food fortification or B-vitamin supplementation, and to examine the associations with Mediterranean diet adherence (MDA). Methods A representative sample of adults aged 18–77 (n=740) provided fasting blood samples and 3-day dietary records. MDA was assessed using the Trichopoulou score. Plasma folate, red blood cell folate (RBCF) and plasma vitamin B 12 were measured via microbiological assays. Riboflavin and vitamin B 6 status were determined by erythrocyte glutathionine reductase (EGRAC) and aspartate aminotransferase activation coefficients (EASTAC), respectively. Results Intake below estimated average requirement was observed in 61.8% (for folate), 6.5% (for vitamin B 12 ), 10.9% (for riboflavin), and 5.8% (for vitamin B 6 ). Plasma folate <7 nmol/L, plasma B 12 <148 pmol/L, RBCF <340 nmol/L, EGRAC ≥1.4, and EASTAC ≥1.6 occurred in 18.6%, 1.6%, 1.5%, 35.9%, and 56.0% of participants, respectively. Overall, 82.64% of participants had low MDA (score <6). Participants in the highest MDA quartile had higher folate intake (354.5 vs. 214.9 μg/day; P < 0.001), plasma folate (14.5 vs. 10.0 nmol/L; P < 0.001), and RBCF (895.7 vs. 692.8 nmol/L; P < 0.001) compared to those in the lowest quartile (score ≤2). Nevertheless, 15.5% of high-MDA individuals did not meet the folate average requirements, and 8.5% had folate deficiencies. Conclusions Higher MDA was associated with better folate intake and status. However, only 17.4 % of the population had high MDA. Plasma folate deficiency affected 18% of the population and still occurred in the high MDA group. The results suggest that a fortification policy is required, to prevent folate deficiency in the population.