Context: Low serum calcidiol has been associated with multiple comorbidities and mortality but no "safe" range has been found for the upper concentration.Objective: We aim to establish the upper threshold of serum calcidiol, beyond which there is an increased risk for acute coronary syndrome and/or mortality.Design, Setting, and Participants: We extracted data for 1 282 822 Clalit Health Services members aged Ͼ45 between July 2007 and December 2011. Records of mortality or acute coronary syndrome were extracted during the follow-up period. Kaplan-Meier analysis calculated time to episode and Cox regression models generated adjusted hazard ratios for episode by calcidiol group (Ͻ10, 10.1-20, 20.1-36, and Ͼ36.1 ng/mL).Outcome Measures: Acute coronary syndrome subsuming all-cause mortality.Results: During the 54-month study period, 422 822 Clalit Health Services members were tested for calcidiol, of which 12 280 died of any cause (905 with acute coronary syndrome) and 3933 were diagnosed with acute coronary syndrome. Compared to those with 20 -36 ng/mL, the adjusted hazard ratios among those with levels of Ͻ10, 10 -20, and Ͼ36 ng/mL were 1.88 (confidence interval [CI]: 1.80 -1.96), 1.25 (CI: 1.21-1.30), and 1.13 (CI: 1.04 -1.22) (P Ͻ .05), respectively. Limitations:The study cohort comprised only 30% of the population, those tested for vitamin D. The small sample size of those with calcidiol Ͼ36 ng/mL prevented further analysis of this group. Conclusions:Vitamin D in the 20 -36 ng/mL range was associated with the lowest risk for mortality and morbidity. The hazard ratio below and above this range increases significantly. (J Clin Endocrinol Metab 98: 2160 -2167, 2013) T here is increasing evidence over the last several years of the pivotal role of vitamin D in human physiology. Evidence from multiple studies showed that low levels of serum calcidiol raise the risk of various morbidities (1)(2)(3)(4)(5) and confirmed the vital influence of vitamin D on human health with its direct involvement in more than 3000 genes (6) and indirect involvement in many others (7). There is also compelling evidence regarding the influence of low

It has recently been well established that the overall utilization of protein by ruminants represents the result of two opposing processes of ammonia utilization: part of the ammonia produced by the decomposition of food protein may be excreted as urea in the urine, and thus lost to the animal, and part may be built into valuable microbial protein and utilized by the host animal. However, only a few assessments of the nutritive value of proteins supplied in different types of feeds have been conducted on the basis of the metabolic fate of proteins in the ruminant.It was found in this laboratory (Tagari, Ascarelli & Bondi, 1962) that a decrease in solubility of different protein feeds as a result of heat treatment, such as the toasting of soya-bean meal, is accompanied by improved utilization (cf. Chalmers, 1961 b ; Sherrod & Tillman, 1962). The reason given for this was that highly soluble proteins such as those of untoasted soya-bean meal are degraded in the rumen to NH, at a rate too rapid for efficient utilization.Two further aspects of this problem are considered in this paper. Supplying excess protein to cattle is typical of the feeding practice prevailing in many countries. This is so during the greater part of the year in Israel, where protein-rich feeds, such as leguminous forage are more plentiful during the winter than are carbohydrate-rich foods. Most practical rations that could be formulated to meet the energy requirements of ruminants for that season would of necessity include a considerable excess of protein. The influence of giving a surplus of proteins on the metabolic reactions occurring in the rumen has therefore been studied. Lewis, 1957Lewis, , 1962; Phillipson, Dobson, Blackburn & Brown, 1962) noted that the addition of readily available carbohydrates to protein-rich diets considerably depressed the NH, concentration in the rumen liquor. We, therefore, made experiments to determine whether the utilization of surplus proteins could be improved by substituting starch for the carbohydrates of the roughage in the diet and whether the concentration of protein-breakdown products in the rumen, particularly the concentration of NH, in the rumen liquor and of urea in the blood, could be used for estimating the efficiency of protein utilization. I964 E X P E R I M E N T A L A N D RESUlLTS Animals and treatmentLambs and adult male and female sheep of the Awassi breed were used. The content of digestible crude protein and the starch equivalent of the various foods in the diets are given in Table I. T h e animals had free access to water and mineral lick. Tables 1-3 on the assumption that the energy content of the rations was adjusted to the theoretical requirements with cottonseed hulls, grain or starch. Sampling. Samples of rumen liquor were removed by suction through a Polythene tube of internal diameter 5 mm. Samples of blood for urea estimation were withdrawn from the jugular vein before the morning feeding and also later, after different time intervals.The analysis of rumen liquor and blood wa...

BACKGROUND Recent studies suggest a link between vitamin D deficiency and Covid-19 infection. In our population we observe major differences in Covid-19 incidence in ethnic groups and genders in each group. METHODS We carried out a population-based study among 4.6 million members of Clalit Health Services (CHS). We collected results from vitamin D tests performed between 2010 and 2019 and used weighted linear regression to assess the relationship between prevalence of vitamin D deficiency and Covid-19 incidence in 200 localities. Additionally, we matched 52,405 infected patients with 524,050 control individuals of the same sex, age, geographical region and used conditional logistic regression to assess the relationship between baseline vitamin D levels, acquisition of vitamin D supplements in the last 4 months, and positive Covid-19. RESULTS We observe a highly significant correlation between prevalence of vitamin D deficiency and Covid-19 incidence, and between female-to-male ratio for severe vitamin D deficiency and female-to-male ratio for Covid-19 incidence in localities (P<0.001). In the matched cohort, we found a significant association between low vitamin D levels and the risk of Covid-19, with the highest risk observed for severe vitamin D deficiency. A significant protective effect was observed for members who acquired liquid vitamin D formulations (drops) in the last 4 months. CONCLUSION In this large observational population study, we show a strong association between vitamin D deficiency and Covid-19 occurrence. After adjustment for baseline characteristics and prior vitamin D levels, acquisition of liquid vitamin D formulations is associated with decreased risk for Covid-19 infection.

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