Determinants of serum 25-hydroxyvitamin d levels in healthy young adults living in the Western Cape, South Africa

Background: Vitamin D deficiency is fast emerging as a global pandemic. In South Africa few studies have been conducted to determine the vitamin D status of the healthy population.Methods: This prospective study with an analytical component investigated vitamin D status of healthy undergraduate students at two time points (winter and summer) at Stellenbosch University. Serum 25(OH)D was determined, anthropometric measurements taken and dietary vitamin D intake estimated (food-frequency questionnaire). Skin tone was determined (Fitzpatrick skin type classification), and a skin reflectometry device used to measure dermal melanin content.Results: Results of 242 students indicated a mean serum 25(OH)D of 63.80 ± 41.35 ng/ml and a high prevalence of vitamin D sufficiency (88%). Significantly more females experienced suboptimal vitamin D levels than males (18 vs. 5%; p < 0.01). Participants with lighter skin tones had higher levels of 25(OH)D than those with darker skin tones (chi-square = 24.02; p = 0.02). The majority (60.74%) had a normal BMI, although there was no significant relationship between BMI and serum 25 (OH)D (Spearman's r=­0.11; p = 0.09). Total mean dietary vitamin D intake was 7.99 ± 13.81 mcg, with 87.2% having inadequate intake (< 15 mcg). The relationship between total vitamin D intake and serum 25(OH)D was found to be significant in winter (p < 0.001) and summer (p = 0.01). Serum vitamin D levels were significantly higher in the winter phase (p < 0.001).Conclusions: A low prevalence of vitamin D deficiency was found amongst healthy young adults, despite low dietary vitamin D intakes. Significant relationships were found between serum 25(OH)D and gender, skin tone and vitamin D intake. Further studies need to be conducted, especially in high-risk groups, before results are applied to the greater South African public

Detection of anthrax toxin genetic sequences by the solid phase oligo-probes.

Purpose: There is an urgent need to detect a rapid field-based test to detect anthrax. We have developed a rapid, highly sensitive DNA-based method to detect the anthrax toxin lethal factor gene located in pXO1, which is necessary for the pathogenicity of Bacillus anthracis. Materials and Methods: We have adopted the enzyme-linked immunosorbent assay (ELISA) so that instead of capturing antibodies we capture the DNA of the target sequence by a rapid oligo-based hybridization and then detect the captured DNA with another oligoprobe that binds to a different motif of the captured DNA sequences at a dissimilar location. We chose anthrax lethal factor endopeptidase sequences located in pXO1 and used complementary oligoprobe, conjugated with biotin, to detect the captured anthrax specific sequence by the streptavidin-peroxidase-based colorimetric assay. Result: Our system can detect picomoles (pMoles) of anthrax (approximately 33 spores of anthrax) and is >1000 times more sensitive than the current ELISA, which has a detection range of 0.1 to 1.0 ng/mL. False positive results can be minimized when various parameters and the colour development steps are optimized. Conclusion: Our results suggest that this assay can be adapted for the rapid detection of minuscule amounts of the anthrax spores that are aerosolized in the case of a bioterrorism attack. This detection system does not require polymerase chain reaction (PCR) step and can be more specific than the antibody method. This method can also detect genetically engineered anthrax. Since, the antibody method is so specific to the protein epitope that bioengineered versions of anthrax may not be detected.