The etiology of osteoporosis associated with rheumatoid arthritis (RA) is unknown. We studied the calcium and vitamin D metabolism in 143 women with RA (mean age 50.7 years). Albumin corrected serum calcium was normal. Serum alkaline phosphatase was increased in 29 percent of cases. Serum vitamin D levels were frequently very low. In 16 percent of the RA patients serum 25(OH)D concentration was below 12.5 nmol/L, which is arbitrarily considered as the limit of vitamin D deficiency osteomalacia. In the winter season 73 percent of the patients had serum 1,25(OH)2D levels below the seasonally adjusted normal range. The lowest values were found in patients with high disease activity. We suggest that there is a disturbance in vitamin D metabolism in RA. This might play a role in osteoporosis associated with RA.

Low Serum Vitamin D Metabolites in Women with Rheumatoid Arthritis

The evolution of our understanding of the biological impact of vitamin D is briefly reviewed, with a focus on the physiology and endocrinology of the vitamin D system. This chapter attempts to bring the molecular discoveries in vitamin D metabolism and mechanisms of action into focus on known physiology and endocrinology. The latest developments on metabolism of vitamin D, the enzymes involved, and the genes responsible are presented. The impact of the molecular discoveries on current views of the importance of vitamin D in public health is also presented.

The Functional Metabolism and Molecular Biology of Vitamin D Action

Summary
Lipophilic bioactive compounds such as lipids, vitamins and phytochemicals serve important antioxidant, functional, nutritional and structural roles in the human body. Colloidal systems such as emulsions are particularly suitable matrices for the protection and delivery of these compounds. This article summarises the principal lipophilic bioactives important for human health and challenges associated with their delivery. It discusses the compositional and physical characteristics of emulsions in relation to bioactive delivery, and chemical stability aspects to consider when engineering efficient emulsion delivery systems. The literature shows that aspects such as oil type, droplet size, interfacial composition and solubilisation capacity impact bioactive availability and that their effects are bioactive specific. Therefore, emulsions must be tailored to the bioactives delivered. Much of the present knowledge is based on in vitro studies, and more data from animal and human models are required to better understand the relationship between emulsion characteristics and bioavailability of lipophilic bioactives.

Designing emulsion droplets of foods and beverages to enhance delivery of lipophilic bioactive components – a review of recent advances

Publisher Summary This chapter reviews the literature on the application of organ culture to the study of vitamins and hormones. The organ culture technique enables part of a complicated problem to be isolated from the general confusion of the body so that it may be studied under controlled, simplified-and yet abnormal conditions. Seeking for the primary cause of some phenomenon in vivo is often like looking for a needle in a haystack. In organ culture, the main object is to preserve the characteristic structure and functional activities of tissues in a condition resembling as closely as possible that of the same organ in the body. Used in this way, as an ancillary technique to studies on the intact animal, organ culture is an extremely valuable tool for a wide variety of problems.

The role of organ cultures in the study of vitamins and hormones.

Cerebral oxidative damage is a feature of aging and is increased in a number of neurodegenerative diseases. We pursued the gene-environment interaction of lack of apolipoprotein E (apoE) and modulation of dietary alpha-tocopherol on cerebral oxidative damage in aged male and female mice by quantifying the major isomers of cerebral isoprostanes, derived from arachidonic acid (AA) oxidation, and neuroprostanes, derived from docosahexaenoic acid (DHA) oxidation. Mice fed alpha-tocopherol-deficient, normal, or -supplemented diet had undetectable, 4486 +/- 215, or 6406 +/- 254 ng of alpha-tocopherol per gram of brain tissue (p < 0.0001), respectively. Two factors, male gender and lack of apoE, combined to increase cerebral AA oxidation by 28%, whereas three factors, male gender, lack of apoE, and deficiency in alpha-tocopherol, combined to increase cerebral DHA oxidation by 81%. alpha-Tocopherol supplementation decreased cerebral isoprostanes but not neuroprostanes and enhanced DHA, but not AA, endoperoxide reduction in vivo and in vitro. These results demonstrated that the interaction of gender, inherited susceptibilities, and dietary alpha-tocopherol contributed differently to oxidative damage to cerebral AA and DHA in aged mice.

https://www.jneurosci.org/content/jneuro/21/16/5993.full.pdf

Interactions between Apolipoprotein E Gene and Dietary α-Tocopherol Influence Cerebral Oxidative Damage in Aged Mice

Abstract As consequence of the steady increase in processing foods consumption, especially because of the current lifestyles of the population, the industry is always creating novel process technology to improve quality, productivity, and attendance of the new markets. Nevertheless, these new technologies, covering thermal and non-thermal processing, affect the value nutritional of food. The vitamins play an important role in the health and can be affected by industrial processing. Modern food processing methods based on short-term treatment such as pulsed electric fields; osmotic dehydration, radiation and high-pressure processing cause negligible degradation of carotenoid. For example, it has been reported that ohmic heating causes no change in carotenoid content; while microwave heating and freeze-drying caused the lowest degradation of carotenoid. Ultrasound treatment of food changed carotenoids into colorless and unknown compounds. These results indicate that although heating processes in short time had a lower degrading effect on carotenoid content, they should be used cautiously to cause the lowest impact on carotenoid content. Regarding the light effect on carotenoid degradation, it has been reported that degradation rate is higher in samples stored at light compared to those kept in darkness. In general, carotenoid degradation can be lowered by reduction temperature, processing time, light and oxygen and application of antioxidants. In this chapter, the effects of processing on bioavailability and bioaccessibility of fat-soluble vitamins were discussed.

E Kodicek

Papers

Fat-Soluble Vitamins