Estimated Dietary Intakes of Vitamin A5

BACKGROUND: A new vitamin concept, termed vitamin A5, an umbrella term for vitamin A derivatives being direct nutritional precursors for 9- cis-13,14-dihydroretinoic acid and further induction of RXR-signaling, was recently identified with global importance for mental health and healthy brain and nerve functions. Dietary recommendations in the range of 1.1 (0.5-1.8) mg vitamin A5 / day were suggested by an international expert consortium. The ensuing question arises as to the current daily dietary intake amounts in Western civilization.

METHODS: Addressing this answer included calculating the intake based on known amounts of vitamin A5 in frequently consumed food items of the human diet that are high in this vitamin, as well as the known daily dietary intake amounts of those selected food components in Westernized countries.

RESULTS: Regarding food items, amounts of vitamin A5 in the form of provitamin A5 (i.e., 9- cis-beta-carotene (9CBC)), the predominant form in the diet, were found to range from 0.1 to 39 µg 9CBC / g for individual fruits and vegetables, with the highest concentrations being in leafy vegetables. The average intake amounts of vitamin A5 in adults of the general population following a Western lifestyle in Europe averaged 0.9, with a range from 0.5 (for Austria) to 1.3 (for Italy) mg 9CBC/day. Furthermore, based on our calculations, large parts, i.e., approximately two-thirds, of the population are low, even too low (<1.1 mg/day), in daily vitamin A5 intake.

CONCLUSION: In addition to the importance of nudging the population toward a regrettably non-well-accepted higher intake of fruits and vegetables, an additional fortification and supplementation of vitamin A5 could be considered, similar to other micronutrients that are low in a Westernized diet.