Results:The daily dietary calcium intake of both the urban and rural populations was low compared with the recommended dietary allowances issued by the Indian Council of Medical Research. Dietary calcium and phosphorous were significantly lower in rural adults than in urban adults (P 0.0001). The dietary phytate-to-calcium ratio was higher in rural subjects than in urban subjects (P 0.0001). The 25(OH)D concentrations of the rural subjects were higher than those of urban subjects (P 0.001), both men and women. In the rural subjects, 25(OH)D-deficient (20 ng/mL), -insufficient (20 -30 ng/mL), and -sufficient (30 ng/mL) states were observed in 44%, 39.5%, and 16.5% of the men and 70%, 29%, and 1% of the women, respectively. In the urban subjects, 25(OH)Ddeficient, -insufficient, and -sufficient states were observed in 62%, 26%, and 12% of the men and 75%, 19%, and 6% of the women, respectively. Conclusions: Low dietary calcium intake and 25(OH)D concentrations were associated with deleterious effects on bone mineral homeostasis. Prospective longitudinal studies are required to assess the effect on bone mineral density, a surrogate marker for fracture risk and fracture rates.Am J Clin Nutr 2007;85:1062-7.

Background: Little if any cutaneous production of vitamin D3 occurs at latitudes above and below 35° N and 35° S during the winter months. It was postulated that those residing in tropics synthesize enough vitamin D3 year round. Several studies have documented the effect of latitude, season and time of the day on the cutaneous production of vitamin D3 in an ampoule model. Studies from India have shown high prevalence of vitamin D deficiency despite abundant sunshine. Methods: We studied the influence of season and time of the day on synthesis of previtamin D3 in an ampoule model in Tirupati, (latitude 13.40° N and longitude 77.2° E) south India, between May 2007 to August 2008. Sealed borosilicate glass ampoules containing 50 μg of 7-DHC in 1 ml of methanol were exposed to sunlight hourly from 8 a.m. until 4 p.m. The percent conversion of 7-DHC to previtamin D3 and its photoproducts and the percent of previtamin D3 and vitamin D3 formed was estimated and related to solar zenith angle. Results: The percent conversion of 7-DHC to previtamin D3 and its photoproducts and formation of previtamin D3 and vitamin D3 was maximal between 11 a.m. to 2 p.m. of the day during the entire year (median 11.5% and 10.2% respectively at 12.30 p.m.). Conclusions: Therefore at this latitude exposure to sunlight between the hours of 11 a.m. and 2 p.m. will promote vitamin D production in the skin year round.

Yeast strains are commonly associated with sugar rich environments. Various fruit samples were selected as source for isolating yeast cells. The isolated cultures were identified at Genus level by colony morphology, biochemical characteristics and cell morphological characters. An attempt has been made to check the viability of yeast cells under different concentrations of ethanol. Ethanol tolerance of each strain was studied by allowing the yeast to grow in liquid YEPD (Yeast Extract Peptone Dextrose) medium having different concentrations of ethanol. A total of fifteen yeast strains isolated from different samples were used for the study. Seven strains of Saccharomyces cerevisiae obtained from different fruit sources were screened for ethanol tolerance. The results obtained in this study show a range of tolerance levels between 7%-12% in all the stains. Further, the cluster analysis based on 22 RAPD (Random Amplified polymorphic DNA) bands revealed polymorphisms in these seven Saccharomyces strains.

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