Fat-Soluble Vitamins
Luke R. Bucci in Nutrition Applied to Injury Rehabilitation and Sports Medicine, 2020
Major dietary sources for vitamin E are wheat germ oil, rice bran oil, wheat germ, vegetable oils, nuts, seeds, cereals, and green leafy vegetables.505,509 The two oils most consumed in the U.S., soybean and corn oils, have very little d-α-tocopherol content, but rather have mostly d-δ-tocopherol content. With increasing usage of vitamin E as a food preservative and additive, vitamin E contents of prepared foods can vary widely. Some foods show seasonal variation of vitamin E contents. Many processes can destroy vitamin E in foods. The list includes exposure to air (oxidation), drying in presence of air and sunlight, addition of organic acids, milling, refining of grains and oils, irradiation, canning, and exposure to peroxidized (rancid) lipids.509 Natural sources of tocopherols are always unesterified, while natural sources of tocotrienols are sometimes esterified. Since plants, but not animals, synthesize vitamin E, animal foodstuffs have very low levels of vitamin E.
Oxidants and Antioxidants
P. K. Shah in Risk Factors in Coronary Artery Disease, 2006
The recommended daily intake of vitamin E is 10 mg. The major dietary sources of vitamin E are vegetable oils, such as olive and sunflower oil. Wheat germs and green vegetables are also good sources of vitamin E. The daily intake of vitamin E in olive oil-based Mediterranean diet is about 20 mg. Beta-carotene is present in yellow, red, and dark green vegetables such as carrots, tomatoes, yellow pumpkin, yellow chili, apricot, and beetroot. To reach a daily intake of 20 mg of beta-carotene (a supplement level commonly used in intervention trials), one should eat at least 290 g of carrots, 2496 g of tomatoes, or 2395 g of yellow chili. The recommended intake of vitamin C is 50 mg. An orange or a grapefruit per day is sufficient to meet this requirement (3).
Chronic Liver Disease
Praveen S. Goday, Cassandra L. S. Walia in Pediatric Nutrition for Dietitians, 2022
Vitamin E is an antioxidant that plays a role in the health of the nervous system, retina, and skeletal muscle. Vitamin E deficiency can lead to neurologic impairment, characterized by hyporeflexia, peripheral neuropathy, ataxia, and proximal muscle weakness. Vitamin E deficiency can be assessed by the serum vitamin E level. Vitamin E, however, circulates in lipoproteins, and as such can be falsely elevated in cholestasis. Therefore, ideally a vitamin E to total lipid ratio (α-tocopherol:total lipid) should be used in children with cholestasis to screen for deficiency, with a ratio of <0.6 mg/g in children <1 year of age and <0.8 mg/g in children >1 year of age indicating deficiency. Alternatively, an α-tocopherol:cholesterol ratio has been proposed, with a cutoff of <2.47 mg/g indicating deficiency.
Vitamin E for the management of major depressive disorder: possible role of the anti-inflammatory and antioxidant systems
Published in Nutritional Neuroscience, 2022
Luana M. Manosso, Anderson Camargo, Alcir L. Dafre, Ana Lúcia S. Rodrigues
Vitamin E is a fat-soluble vitamin that was discovered in 1922 [8]. Nowadays, eight chemically different analogs of this vitamin have been reported to be present in food, alpha (α), beta (β), gamma (γ) and delta (δ)-tocopherol and α-, β-, γ- and δ-tocotrienols [9]. Tocopherols and tocotrienols have a similar structure that includes a hydrophilic chromanol ring and an isoprenoid side chain. The difference between them is that tocopherol has a saturated chain, whereas tocotrienol has an unsaturated chain. The differences between the tocopherol analogous α, β, γ, and δ are the number and location of methyl groups in the chromanol ring [10,11]. Among the eight analogs of vitamin E, α-tocopherol is the most abundant in foods and the primary source of this vitamin. Most notable among the food sources of vitamin E are vegetable oils, seeds (especially almonds, peanuts, and sunflower), breakfast cereals fortified with vitamin E, eggs, and some fruit and vegetables [12,13], as shown in Figure 1. According to ‘Dietary Reference Intakes’ the recommended daily intake of vitamin E for an average-sized adult is 15 mg [14].
ALSUntangled 55: vitamin E (α-tocopherol)
Published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 2021
Bedlack Richard
As stated above, the recommended daily allowance of vitamin E is 15 mg daily (2). Available safety data from animal studies and clinical trials suggests that daily doses of up to 1000 mg are likely to be safe for periods of at least 18 months (87). Safety analyses in PALS from both the 1000 mg per day for 12 months trial and the high dose vitamin E for 18 months trial suggested that there is no discernable difference in adverse events between vitamin E and placebo for the regimens used in these trials (76,79). PALS receiving mega dosages (10,000 mg daily) for 6 months in a case series were said to “tolerate” the dose but no formal listing of adverse events was provided (72). Unless under a physician’s close supervision, no one should initiate a vitamin E supplement if they have a bleeding disorder or are taking an anticoagulant like warfarin. Vitamin E supplementation can lead to decreased vitamin K, inhibited platelet aggregation and reduced platelet–endothelial adhesion that can cause life-threatening hemorrhage (88–90). One large, randomized, placebo-controlled trial in healthy men suggested that vitamin E supplementation over very long periods of time (7–10 years) can slightly increase the risk of prostate cancer (91). However, two other large long-duration trials did not find this same increased risk (92,93).
Mechanistic links between vitamin deficiencies and diabetes mellitus: a review
Published in Egyptian Journal of Basic and Applied Sciences, 2021
Tajudeen O. Yahaya, AbdulRahman B. Yusuf, Jamilu K. Danjuma, Bello M. Usman, Yahaya M. Ishiaku
The findings of many studies suggest that vitamin E supplementation can effectively normalize blood glucose levels. In a study that monitored the effects of oral insulin and vitamin E supplementation on some type 1 and 2 diabetic patients, the patients who were on vitamin E supplementation showed better glycemic control and a slower progression of diabetic complications [81]. Tocotrienol-rich fraction supplementation reduces hyperglycemia-induced skeletal muscle damage through regulation of insulin signaling and oxidative stress in type 2 diabetic mice [82]. In a systematic review and meta-analysis of 33 clinical trials involving 2102 individuals, vitamin E supplementation (≥ 700 mg/day) significantly reduced C-reactive protein (CRP), cytokines, tumor necrosis factor-α (TNF-α), and insulin resistance [83]. The mechanistic links between vitamin E deficiency and DM are summarized in Figure 7.
Related Knowledge Centers
- Antioxidant
- Dietary Supplement
- Neurological Disorder
- Reactive Oxygen Species
- Tocopherol
- Cardiovascular Disease
- Cell Membrane
- Cancer
- Vitamin E Deficiency
- Fat