Rediscovering vitamin D

Over the past 2 years there has been a radical change in standard clinical practice with respect to vitamin D. As a result of a growing body of knowledgeable physicians are assessing the vitamin D nutritional status of their patients and prescribing aggressive repletion regimens of a vitamin D supplement. The present paper summarizes some basic information about this essential nutrient and reviews some of the more recent data implicating vitamin D deficiency in disease etiology with an emphasis on cardiovascular disease and cancer. Finally a rational approach to the dosing of vitamin D in different patient populations is provided

Nicotinamide adenine dinucleotide, the sirtuins, and the secret of a long health span

The sirtuins constitute a family of proteins with broad enzymatic activities that have an absolute requirement for nicotinamide adenine dinucleotide (NAD+) as a cosubstrate. Evidence has been mounting over the past 15 years or so that implicates the sirtuins in a vast array of critical cellular functions. In addition to transcription silencing and DNA repair, these functions include the regulation of ion channels, neuronal functions, cell growth, circadian rhythm, inflammatory response, mitochondrial biogenesis, insulin secretion, fat oxidation, and glucose metabolism. The sirtuins are critical for maintaining mitochondrial health, energy homeostasis, and redox balance. The sirtuins are widely believed to be behind the extension of lifespan brought about by calorie restriction and fasting. Changes in sirtuins activities have been linked to most age-related pathologies including cardiovascular disease, cancer, and Alzheimer's disease (AD). NAD+ is familiar to students of biological chemistry as an enzyme cofactor whose presence is essential for the progress of hundreds of vital biochemical reactions. This compound is present in virtually all living organisms. Simply put, without NAD+, life as we know it would not exist. The progress of these reactions requires the cleavage of NAD+, whose intracellular levels are known to decline steadily with age. This decline and its negative impact on the activities of these enzymes and on metabolism in general are implicated in the development of metabolic and age-linked diseases. Therefore, maintaining high intracellular NAD+ levels throughout life may not only extend the lifespan but is likely to extend the health span as well. In this paper I review how the intracellular pool of NAD+ is maintained and summarize the functions and regulation of sirtuins activities.</jats:p

Measuring obesity: Fat or fit!

Obesity is widely recognized as a major global health challenge because of its strong association with multiple cardiometabolic risk factors including diabetes, hypertension, and coronary artery disease. It compromises the quality of life and shortens life expectancy. This minireview discusses firstly the physiological mechanisms involved in energy homeostasis including peptidergic signalling of hunger and satiety from the GI tract mediated by the gut hormones (ghrelin, CCK, PYY, GIP, GLP-1,), and the status of energy stores from the adipose tissue mediated primarily by leptin, secondly, the field methods used in clinical practice to estimate the degree of obesity and lastly, management of the obese patient.</jats:p