Vitamin A beta-carotene

Edes, T. E., Gysbers, D. G., Buckley, C. S., and Thornton, W. H., Jr. (1991). Exposure to the carcinogen benzopyrene depletes tissue vitamin A Beta-carotene prevents depletion. 

With mesoporous materials (both silica and silicon), one can provide nanoentrapment of nutrients, as opposed to microencapsulation. This can provide not only protection from environmental parameters (see Table 2) but also bioavailability improvements for hydrophobic nutrients (Canham 2007). Nutrients loaded to date in mesoporous silicon include vitamin A, beta-carotene, vitamin E, fish oils, lycopene, coenzyme QIO, and curcumin. Table 3 presents an example of loading... 

Aloe vera contains vitamins A (beta-carotene), C and E, B12, folic acid, and choline among which vitamin A, C and E act as antioxidants. 

Because orlistat reduces the absorption of some fat-soluble vitamins and beta-carotene, counsel patients to take a multivitamin containing fat-soluble vitamins to ensure adequate nutrition. Instruct the patient to take the supplement once a day, at least 2 hours before or after the administration of orlistat, such as at bedtime. Doses greater than 120 mg 3 times a day have not been shown to provide additional benefit. 

Vitamins C and A, beta carotene, riboflavin, folate, various minerals, and fiber these are needed to prevent deficiency disorders and may protect against cancer... 

A good source of vitamin C, beta carotene, and potassium... 

Use of orlistat could interfere with the body s absorption of fat-soluble vitamins and beta carotene. Long-term use could result in deficiencies of vitamins A, D, E, and K, and beta carotene. Patients are advised to take supplements. Another possible side effect is calcium deficiency. 

The lung also possesses nonenzymatic antioxidants such as vitamin E, beta-carotene, vitamin C, and uric acid. Vitamin E is lipid-soluble and partitions into lipid membranes, where it is positioned optimally for maximal antioxidant effectiveness. Vitamin E converts superoxide anion, hydroxyl radical, and lipid peroxyl radicals to less reactive oxygen metabolites. Beta-carotene also accumulates in cell membranes and is a metabolic precursor to vitamin A. Furthermore, it can scavenge superoxide anion and react directly with peroxyl-free radicals, thereby serving as an additional lipid-soluble antioxidant. Vitamin C is widely available in both extracellular and intracellular spaces where it can participate in redox reactions. Vitamin C can directly scavenge superoxide and hydroxyl radical. Uric acid formed by the catabolism of purines also has antioxidant properties and primarily scavenges hydroxyl radical and peroxyl radicals from lipid peroxidation. 

A-2 Vitamin A consists of three biologically active molecules, retinol, retinal (retinaldehyde) and retinoic acid. Each of these compounds are derived from a group of molecules know as carotenoids also referred to as the provitamin A. Beta-carotene, which consists of two molecules of retinal linked at their aldehyde ends. 

Van Hoydonck, P.G., Temme, E.H., and Schouten, E.G., A dietary oxidative balance score of vitamin C, beta-carotene and iron intakes and mortality risk in male smoking Belgians, J. Nutr., 132, 756,2002. 

The active forms of vitamin A that were associated with the defects are found in fortified breakfast cereals, liver, and some vitamin snpplements. Beta-carotene, a form of vitamin A that has not been linked to birth defects, is now nsed in many prenatal vitamin snpplements. Beta-carotene is a plant-based vitamin A source that is converted into an active form of vitamin A once ingested. 

Vitamins are classified by their solubiUty characteristics iato fat-soluble and water-soluble groups. The fat-soluble vitamins A, E, and K result from the isoprenoid biosynthetic pathway. Vitamin A is derived by enzymic cleavage of the symmetrical C q beta-carotene, also known as pro-vitamin A. Vitamins E and K result from condensations of phytyldiphosphate (C2q) with aromatic components derived from shikimic acid. Vitamin D results from photochemical ring opening of 7-dehydrocholesterol, itself derived from squalene (C q). 

This means that in the strictest sense, PABA is not a vitamin, because the body can manufacture it. But in this sense, too, vitamin A is not technically a vitamin, as the body makes that from beta-carotene. 

The body turns beta-carotene into vitamin A, and it is sometimes added to foods or vitamin supplements as a nutrient. 

BARTH T J, ZOLER J, KUBELER A, BORN A I and OSSWALD H (1997) Redifferentiation of oral dysplasic mucosa by the application of the anti-oxidants beta-carotene, a-tocopherol and vitamin C. Int J Vitam Nutr Res 67(5) 368-76. 

OMENN G S, GOODMAN G E, THORNQUIST M D, BALMES J, CULLEN M R, GLASS A, KEOGH J P, MEYSKENS F L, VALANIS B, WILLIAMS J H, BARNHART S and HAMMAR S (1996) Effects of a combination of beta-carotene and vitamin A on lung cancer and cardiovascular disease. N EnglJ Med 1150-1155. 

Olson, J.A. and Hayaishi, O., The enzymatic cleavage of beta-carotene into vitamin A by soluble enzymes of rat liver and intestine, Proc. Natl Acad. Sci. USA, 54,1364,1965. 

Lindqvist, A. and Andersson, S., Biochemical properties of purified recombinant human beta-carotene 15,15-monooxygenase, J. Biol. Chem., 277, 23942, 2002. Krinsky, N.I., Cornwell, D.G., and Oncley, J.I., The transport of vitamin A and carotenoids in human plasma. Arch. Biochem. Biophys., 73, 233, 1958. 

The stability of individual analytes within a matrix material is often quite variable. A good example is shown by NIST SRM 968b fat soluble vitamins and cholesterol in serum. The material must be shipped and stored at -8o°C. The SRM is certified for a range of vitamins, most of which are quite stable at -20°C, or even +4°C, but the beta-carotene and other components are not. It is therefore essential to ensure the material, if the carotene components are of interest, is shipped and stored correctly. 

There are no approved pharmacologic treatments for atrophic AMD. The Age-Related Eye Disease Study showed that a supplement containing ascorbic acid 500 mg, vitamin E 400 IU, beta carotene 15 mg, zinc oxide 80 mg, and cupric oxide 2 mg reduced the rate of clinical progression of all types of AMD by 28% in patients with at least intermediate macular degeneration. No benefit was seen in patients with earlier stages of age-related maculopathy however, the duration of the study may have been insufficient to detect this benefit.25... 

Free radicals can cause a lot of damage in the body. Vitamin C, vitamin E, and beta-carotene are known as antioxidants. All of... 

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