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Micronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
An excessive intake of food rich in carotenoids such as carrots, tomatoes, can result in a distinct orange-yellow color of the skin, called hypercarotenemia (9, 58). This symptom can be reversed by discontinuing beta-carotene ingestion. Unlike preformed vitamin A, beta-carotene is not known to be teratogenic or lead to reproductive toxicity or birth defect. Carotenes are strong antioxidants. High doses of beta-carotene supplements (20–30 mg/day) or diets with high levels of carotenoid-rich food for long periods are not associated with toxicity (9, 56). However, supplementation with beta-carotene, with or without retinyl palmitate, for five to eight years has been associated with an increased risk of lung cancer and cardiovascular disease in current and former male and female smokers and in male current and former smokers occupationally exposed to asbestos (56). In addition, beta-carotene supplements (20 mg daily) were also associated with increased mortality, mainly due to lung cancer and ischemic heart disease (56). In contrast, natural foods (fruits and vegetables) rich in beta-carotene or carotenoids protect against lung cancer and prevent heart disease (56).
Prenatal Care
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Gabriele Saccone, Kerri Sendek
In pregnancy, some extra vitamin A is required for growth and tissue maintenance in the fetus, for providing fetal reserves, and for maternal metabolism. However, vitamin A in its synthetic form as well as in large doses as retinol (preformed vitamin A found in cod liver oil and chicken or beef liver) is teratogenic. It is recommended that pregnant women ingest vitamin A as β-carotene and limit the ingestion of retinol during pregnancy. In vitamin A–deficient populations (where night blindness is present) and in HIV-positive women, vitamin A supplementation reduces maternal night blindness and anemia. Excess vitamin A intake can cause birth defects and miscarriages at doses >25,000 IU/day. Vitamin A supplements should be avoided, with maximum daily intake prior to and during pregnancy probably 5000 IU and certainly ≤10,000 IU, respectively. Vitamin A supplementation may be beneficial in women with vitamin A deficiency, especially in prevention of night blindness, in developing countries. Optimal duration of supplement use cannot be evaluated. One large population-based trial in Nepal shows a possible beneficial effect on maternal mortality after weekly vitamin A supplements. Night blindness, associated with vitamin A deficiency, was assessed in a nested case-control study within this trial and found to be reduced but not eliminated. There is insufficient evidence to support vitamin A supplementation as an intervention for anemia [83, 84].
Nutritional requirements
Published in Judy More, Infant, Child and Adolescent Nutrition, 2021
Vitamin A comes in two forms: retinol in some animal foods (full-fat milk, butter, margarine, egg yolks and liver) and carotene in fruits and vegetables. Carotene is the orange coloured pigments in fruits and vegetables, and is also present in dark green vegetables such as spinach and broccoli.
Construction and evaluation of an antioxidant synergistic system containing vitamin C and vitamin E
Published in Journal of Microencapsulation, 2023
Ran Tao, Qianyu Zhang, Jialing Duan, Ran Chen, Liyun Yao, Ruiteng Zhang, Gang Dong, Huali Chen
The antioxidant activity of the liposomes was evaluated using a β-carotene-linoleic acid model system (Emmons et al.1999). In the β-carotene-linoleic acid system, the yellow-orange colour of β-carotene was readily discoloured by the oxidation of linoleic acid. During oxidation, a hydrogen atom extracted from the active diallyl methylene could form a pentenyl radical. It attacked the highly unsaturated β-carotene molecule and regains a hydrogen atom. The carotene would therefore lose its characteristic orange colour. This oxidation process could be monitored spectrophotometrically. The presence of antioxidants could inhibit the extent of β-carotene damage through the linoleic acid radical and other free radicals formed within the system using its redox potential and other free radicals formed within the system (Vieira et al.1998, Argoti et al.2011). This, therefore, formed the basis for assessing the antioxidant potential of liposomes.
Factors determining the oral absorption and systemic disposition of zeaxanthin in rats: in vitro, in situ, and in vivo evaluations
Published in Pharmaceutical Biology, 2022
Seong‑Wook Seo, Dong‑Gyun Han, Eugene Choi, Min‑Jeong Seo, Im‑Sook Song, In‑Soo Yoon
Carotenoids are a class of naturally occurring yellow, orange, and red pigments, synthesized de novo by photosynthetic plants, algae, bacteria, and fungi (Maoka 2020). Generally, α‑carotene, β‑carotene, β‑cryptoxanthin, lutein, lycopene, and zeaxanthin (Figure 1) are the major dietary carotenoids prevalent in human serum and tissues (Mein et al. 2011; Bernstein et al. 2016; Toti et al. 2018). Carotenoids can be structurally categorized into two classes: carotenes and xanthophylls. Carotenes, such as α‑carotene, β‑carotene, and lycopene, are non‑polar compounds that are pure hydrocarbons without oxygen atoms (Jia et al. 2017). Xanthophylls, such as lutein, zeaxanthin, and β‑cryptoxanthin, are relatively polar carotenoids that contain at least one oxygen atom (Jia et al. 2017). α‑Carotene, β‑carotene, and β‑cryptoxanthin are provitamin A carotenoids that can be metabolized to retinol after administration in the body, whereas lutein, zeaxanthin, and lycopene are non‑provitamin A carotenoids that cannot be metabolized to retinol (Mein et al. 2011).
Role of plant-based diet in late-life cognitive decline: results from the Salus in Apulia Study
Published in Nutritional Neuroscience, 2022
Roberta Zupo, Chiara Griseta, Petronilla Battista, Rossella Donghia, Vito Guerra, Fabio Castellana, Luisa Lampignano, Ilaria Bortone, Madia Lozupone, Gianluigi Giannelli, Giovanni De Pergola, Heiner Boeing, Rodolfo Sardone, Francesco Panza
Regarding the dietary profile, the present findings linked some MeDi foods, but also some others not directly discussed in this context, to a lower cognitive performance but not always in the assumed direction (red meat). The cognitively impaired study group was characterized by a lower vegetables intake, particularly of root vegetables and to a lesser extent fruiting vegetables (i.e. carrots, tomatoes, zucchini, peppers), and of coffee. A common feature of these foods is the rich content of bioactive compounds with beneficial metabolic effects that extend beyond modulating oxidative stress to improving brain functions [34]. The present findings showed that not all plant-foods are equally positively associated with cognitive performance in older age, and that carrots, as dominant root vegetable, could be responsible for the inverse association observed. The β-carotene content of carrots is well known. This is a potent antioxidant and may therefore protect the central nervous system from damage due to age-related tissue oxidation. However, previous findings demonstrated that short-term β-carotene supplementation did not affect cognitive performance [35], although it is quite possible that longer term exposure to β-carotene in the diet may have beneficial effects on cognition. Moreover, since β-carotene (provitamin A) represents the main plant source of this vitamin, the finding regarding root vegetables contributes to the inverse association observed between dietary vitamin A and impaired cognition.