Study of the fluctuation of serum vitamin D concentration with time during the same day and night on a random sample of healthy adults.

BACKGROUND AND AIMS: A common practice in the assessment of vitamin D is to measure its blood level in the morning after overnight fasting. The aim of this study was to measure vitamin D during different times of the day and night for a random sample of healthy individuals, to see if there are significant changes throughout the day and night. METHODS: A cross sectional study was carried out on a total of 52 randomly selected Jordanian healthy volunteers (26 women and 26 men) aged between 18 and 45 years. Six blood samples were taken from each participant on the same study day; 7:30 AM (at fasting), 10:30 AM, 1:30 PM, 4:30 PM, 7:30 PM and at 10:30 PM. An extra 7th blood sample was taken next morning at 7:30 AM (after fasting overnight). RESULTS: There was a significant difference (P < 0.05) between mean serum vitamin D level at 7:30 AM (19.64 ± 0.26 ng/ml) and 1:30 PM (20.60 ± 0.26 ng/ml), and 4:30 PM (20.61 ± 0.26 ng/ml), P-value 0.0096 and 0.0090, respectively. When taken into consideration the effect of exposure to the sun and the time, there was a significant difference (P ˂ 0.05) between the two groups (group 1: sun protected group, and group 2: sun exposure group) at different times on the same day and the morning of the second day (P-value = 0.0113). CONCLUSION: The serum vitamin D concentrations vary during different times of the day, night and next morning, and that its concentration at fasting does not represent its true value.

Effect of bitter vetch (Vicia ervilia) seeds as a replacement protein source of soybean meal on performance and carcass characteristics of finishing Awassi lambs.

The objective of this study was to evaluate the effects of replacing the protein source of soybean meal (SBM) with different levels of bitter vetch seeds (BVS) in the diets of finishing Awassi ram lambs on performance, and carcass characteristics. Diets were designed based on replacing SBM with BVS as a percentage of the diet. Diets were: control (0% BVS), substituting 5% of SBM (5% BVS), 10% of SBM (10% BVS) and the entire SBM in the ration with BVS (15% BVS). Forty eight lambs (18.74 +/- 3.95 kg initial body weight and 70 days of age) were randomly assigned to 4 treatment diets (12 lambs/treatment). Lambs were given an adaptation period of 10 days and the experiment lasted for 84 days. At the end of the trial, a digestibility experiment was performed and 6 lambs from each treatment were slaughtered to evaluate carcass characteristics. Average daily gain tended (P = 0.07) to be higher for lambs fed 10% BVS when compared to the other diets. Neutral detergent fiber digestibility was higher (P < 0.01) in control diet compared to the other diets. Fat depth (C) and leg fat depth (L3) tended (0.05 < P < 0.1) to be affected by BVS levels in the diet. Leg total lean % was the highest (P < 0.05) in 5% BVS and 10% BVS diets. These results suggest that substituting SBM with BVS in the diets did not influence performance or carcass characteristics of lambs. However, the cost of ration formulation decreases since SBM is a very expensive component of the ration.