Vitamins for Chronic Disease Prevention in Adults
Context Although vitamin deficiency is encountered infrequently in developed countries, inadequate intake of several vitamins is associated with chronic disease.
Objective To review the clinically important vitamins with regard to their biological effects, food sources, deficiency syndromes, potential for toxicity, and relationship to chronic disease.
Data Sources and Study Selection We searched MEDLINE for English-language articles about vitamins in relation to chronic diseases and their references published from 1966 through January 11, 2002.
Data Extraction We reviewed articles jointly for the most clinically important information, emphasizing randomized trials where available.
Data Synthesis Our review of 9 vitamins showed that elderly people, vegans, alcohol-dependent individuals, and patients with malabsorption are at higher risk of inadequate intake or absorption of several vitamins. Excessive doses of vitamin A during early pregnancy and fat-soluble vitamins taken anytime may result in adverse outcomes. Inadequate folate status is associated with neural tube defect and some cancers. Folate and vitamins B6 and B12 are required for homocysteine metabolism and are associated with coronary heart disease risk. Vitamin E and lycopene may decrease the risk of prostate cancer. Vitamin D is associated with decreased occurrence of fractures when taken with calcium.
Conclusions Some groups of patients are at higher risk for vitamin deficiency and suboptimal vitamin status. Many physicians may be unaware of common food sources of vitamins or unsure which vitamins they should recommend for their patients. Vitamin excess is possible with supplementation, particularly for fat-soluble vitamins. Inadequate intake of several vitamins has been linked to chronic diseases, including coronary heart disease, cancer, and osteoporosis.
 Vitamin effects on the immune system: vitamins A and D take centre stage
Vitamins are essential constituents of our diet that have long been known to influence the immune system. Vitamins A and D have received particular attention in recent years as these vitamins have been shown to have an unexpected and crucial effect on the immune response. We present and discuss our current understanding of the essential roles of vitamins in modulating a broad range of immune processes, such as lymphocyte activation and proliferation, T-helper-cell differentiation, tissue-specific lymphocyte homing, the production of specific antibody isotypes and regulation of the immune response. Finally, we discuss the clinical potential of vitamin A and D metabolites for modulating tissue-specific immune responses and for preventing and/or treating inflammation and autoimmunity.
 Vitamins and minerals: efficacy and safety
Safety and efficacy are crucial but separate issues for vitamin and mineral supplements. Misinterpretation of “safe and adequate” to mean “safety limit” would impose restrictions on vitamin and mineral intakes that are not needed to ensure safety. Substantial evidence indicates that intakes greater than the recommended dietary allowances (RDAs) of certain vitamins and minerals such as calcium, folic acid, vitamin E, selenium, and chromium reduce the risk of certain diseases for some people. Limitation of intakes to the RDAs would preclude reductions in disease risk from these nutrients. The margin of safety between the usual dietary intake and the intake that would produce adverse effects varies greatly among the different nutrients. Very high intakes of vitamins A and D, niacin, pyridoxine, and selenium have produced adverse effects. Many widely discussed putative adverse effects of vitamin C, vitamin E, and trivalent chromium have little factual basis. There is no evidence of adverse effects from beta-carotene supplements except in current heavy smokers.
 Proximate Composition, Vitamin and Anatomical Studies on Gomphrena celosioides
Gomphrena celosioides is an ornamental plant with highly medicinal values. Available information on its anatomical studies is scanty while proximate composition and vitamins investigations are lacking. This study therefore focused on proximate composition, vitamin and anatomical evaluation of its various parts usingstandard methods. Analysis of variance (ANOVA) was employed for data analysis. Moisture, ash and crude fiber were highest in the stem (64.20±0.14, 8.26±0.00 and 18.66±0.01) respectively. Total protein and fat contents were highest in the leaf (0.44±0.00 and 0.52±0.00) respectively while carbohydrate was highest in the root (33.21±0.63). The study on vitamins showed that vitamins A and C contents were highest in leaf (1.96±0.01) and (1.68±0.01) respectively and lowest in root (1.57±0.02) and (1.47±0.01) respectively. Anatomical result revealed similar features in their epidermis and cortex and differences in their vascular bundles arrangement. This work has demonstrated that the plant is highly nutritious. Apart from its use as an ornamental, the parts could be used as food to supplement our daily nutrient needs. Also the anatomical result is an additional aid to the taxonomic characterization of the plant.
 Vitamin D Receptor BsmI Gene Polymorphisms and Gestational Diabetes Mellitus: A Saudi Study
Background: Both vitamin D deficiency and Gestational diabetes (GDM) are common among Saudis. The vitamin D receptor (VDR) gene is a candidate gene for susceptibility to several diseases. Studies on association between VDR polymorphisms and risk of GDM in Saudi populations are yet inconclusive.
Objective: to evaluate the association between Vitamin D receptor gene polymorphisms and genetic susceptibility to gestational diabetes (GDM) in pregnant Saudis.
Subjects & Methods: thirty pregnant Saudi women with diabetes (17 GDM and 13 type 2 diabetes (T2DM) with past history of GDM) were compared to 14 pregnant women with normal glucose tolerance. Patients and controls were recruited at their third trimester from Taibah University medical unit from January to July 2010. Genomic DNA was extracted and the genotyping related to vitamin D receptor BsmI gene single – nucleotide polymorphisms was carried out by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis.
Results: The gene frequency, allele frequency and carriage rate of the VDR polymorphism BsmI did not differ between patients and controls with no significant association with any clinical parameters. The 25 hydroxyl Vitamin D level but not the gene frequency was a significant predictor of history of abortion among diabetics (OR=-0.29, 95% CI -0.081-0.0, p=0.047).
Conclusions: Vitamin D receptor BsmI gene polymorphisms is not associated with gestational diabetes among Saudis. Further studies of other Vitamin D receptor gene polymorphism in combination are required.
 Fairfield, K.M. and Fletcher, R.H., 2002. Vitamins for chronic disease prevention in adults: scientific review. Jama, 287(23), pp.3116-3126.
 Mora, J.R., Iwata, M. and Von Andrian, U.H., 2008. Vitamin effects on the immune system: vitamins A and D take centre stage. Nature Reviews Immunology, 8(9), pp.685-698.
 Hathcock, J.N., 1997. Vitamins and minerals: efficacy and safety. The American journal of clinical nutrition, 66(2), pp.427-437.
 Ilodibia, C.V., Ewere, F.U., Akachukwu, E.E., Adimonyemma, R.N., Igboabuchi, N.A. and Okeke, N.F., 2016. Proximate composition, vitamin and anatomical studies on Gomphrena celosioides. Annual Research & Review in Biology, pp.1-6.
 Tawfeek, M.A., Habib, F.A. and Saultan, E.E.M., 2011. Vitamin D receptor BsmI gene polymorphisms and gestational diabetes mellitus: a Saudi study. Journal of Advances in Medicine and Medical Research, pp.459-468.