We describe a method for the determination of retinol, alpha-tocopherol, and beta-carotene in serum, using a liquid-chromatographic separation with wavelength-programmed ultraviolet/visible absorbance and amperometric electrochemical detection with a glassy carbon electrode. After protein denaturation and addition of an internal standard, tocol, 250-microL samples are twice extracted with hexan...

Dietary vitamin A deficiency causes eye disease in 40 million children each year and places 140 to 250 million at risk for health disorders. Many children in sub-Saharan Africa subsist on maize-based diets. Maize displays considerable natural variation for carotenoid composition, including vitamin A precursors alpha-carotene, beta-carotene, and beta-cryptoxanthin. Through association analysis, ...

The conversion of phytoene into beta-carotene was demonstrated previously in chromoplast membranes prepared from Capsicum fruits (B. Camara et al. 1982 Eur J Biochem 127: 255-258). The direct cyclization of lycopene into beta-carotene and the successful solubilization of the enzymic activity involved in this reaction is reported.

Vitamin A deficiency (VAD) affects over 250 million people worldwide and is one of the most prevalent nutritional deficiencies in developing countries, resulting in significant socio-economic losses. Provitamin A carotenoids such as beta-carotene, are derived from plant foods and are a major source of vitamin A for the majority of the world's population. Several years of intense research has re...

Carotenoids are important for various functions during chick development. Since these pigments cannot be synthesized, they can be considered limited resources that the mother optimally allocates between herself and her offspring (maternal effect). Some studies have examined the effects of carotenoids on growth and immune function but little is known about their role in behaviour. In this study ...

BACKGROUND AND PURPOSE Intake of fruits and vegetables has been related to lower risk of ischemic stroke, but nutrients responsible for this apparent benefit remain ill-defined. Tocopherols (vitamin E) have also been proposed to be protective. METHODS We conducted a prospective, nested case-control analysis among male physicians without diagnosed cardiovascular disease followed-up for up to 1...

Inhibition of experimental oral carcinogenesis by topical beta carotene. by Schwartz, et al. 1986. Harvard School of Dental Medicine. Pub. in Carcinogenesis, May 1986 7(5) 711-715. USA. Beta carotene was found to significantly inhibit the formation of squamous cell carcinoma of hamster buccal pouch when a solution was applied topically three times weekly for 22 weeks in an experiment with 40 ha...

It was determined that lycopene could be cyclized directly by Rhodotorula glutinis. It was also shown the the temperature effect (i.e., increased beta-carotene synthesis in response to lower incubation temperatures) in R. glutinis was controlled by changes in enzyme concentration.

The uptake of dietary lipids from the small intestine is a complex process that depends on the activities of specific membrane receptors with yet unknown regulatory mechanisms. Using both mouse models and human cell lines, we show here that intestinal lipid absorption by the scavenger receptor class B type 1 (SR-BI) is subject to control by retinoid signaling. Retinoic acid via retinoic acid re...

The effect of a biscuit with red palm oil as a source of beta-carotene was compared with the effect of a biscuit with beta-carotene from a synthetic source on the vitamin A status of primary school children in a randomised controlled trial. Children aged 5-11 years (n = 265) were randomly assigned to one of three groups: (1) placebo biscuit; (2) biscuit with synthetic beta-carotene as a vitamin...