The role of carotenoids in the physiological course of pregnancy and their significance in the development of preeclampsia and fetal development delay syndrome

Carotenoids are fat-soluble pigments synthesized by plants and some microorganisms. Thus far, more than 700 carotenoids have been identified and belong to groups of carotenes (e.g., β-carotene, α-carotene, and lycopene) as well as their hydroxylated derivatives-xanthophylls (e.g., lutein and zeaxanthin, β-cryptoxanthin, and astaxanthin). About 50 of these carotenoids can be found in the human diet, mainly of plant origin, and some are present in dietary supplements. Plasma levels of carotenoids are determined by their intakes from the diet, but about 95% of plasma carotenoids are represented by only six compounds: β-carotene, α-carotene, lycopene, and β-cryptoxanthin as well as lutein and zeaxanthin (often analyzed together; the nutritional and health effects of carotenoids are due to their multidirectional biological effects in humans, including antioxidant, anti-inflammatory and immunomodulatory properties). Furthermore, some carotinoids (β-carotene, α-carotene, and β-cryptoxanthin) can be converted to vitamin A in humans, which can contribute to meeting the reguirement for this essential vitamin. The β-carotene conversion ratio to vitamin A is 12:1 (24:1 for others carotinoids), and is altered by individuals vitamin A status, food matrices, food preparations and the fat content of are meal. The WHO estimates the about 19 million pregnant women in low-income countries are affected by vitamin A deficiency. Many biological properties of carotenoids help maintain health by decreasing the risk of chronic non-communicable diseases, such as cancer, cardiovascular disease, some eye disorders and age-related decline in cognitive functions, which has been shown in association studies.