The first harmonised total diet study in Portugal: Vitamin D occurrence and intake assessment.

Vitamin D acts in calcium and phosphate homeostasis and also as an immunomodulatory hormone. To estimate the vitamin D intake by the 'adults' and 'elderly' Portuguese populations TDS methodology was used, since in the absence of skin UVB exposure, food and supplements are the only vitamin D sources. Vitamin D was quantifiable in 78 (24 from the fish group) of the 164 TDS samples. Sea bream contained the most vitamin D (13.8 µg/100 g), followed by plaice (9.2 µg/100 g). MCRA software (semi-probabilistic approach) was used to estimate the median vitamin D intake that ranged between 2.47 ('adults' 'males') - 1.45 ('elderly' 'females') µg/day, well below the Dietary Reference Values (5-15 µg/day). Plaice, sea bream and sardine were the main contributors to intake. A prevalence of 94% inadequate vitamin D intake for 'adults' and 'elderly' was found based on the estimated average requirement of 10 µg/day.