Re-emerging Vitamin D deficiency epidemic and its implications on the public health in the US

Vitamin D is essential in maintaining the bone health and Calcium homeostasis in the body. These actions are mediated through the Vitamin D receptors (VDR) present in cells through which the activated vitamin D acts [1]. In the past, it was known that these receptors existed in the intestine and bone cell. However, recent discovery of VDR in other tissues as well, has broadened the action of Vitamin D and increased its adequate intake [1].^ In the past, Vitamin D deficiency was most common among institutionalized, elderly patients and children and thought to be extinct in the healthy population. However, recent evidence has shown that, prevalence of vitamin D deficiency is increasing into an epidemic status in the overall population of the United States, including the healthy individuals [2-3]. The increased daily-recommended requirement and other multiple factors are responsible for the re-emergence of this epidemic [4-5]. Some of these factors could be used to control the epidemic. Studies have also shown the association between vitamin D deficiency and increased risk for developing chronic diseases such as diabetes, hypertension, multiple sclerosis, arthritis, and some fatal cancers like prostate, colon and breast cancers [1, 4, 6-14]. This issue results in increased disease burden, morbidity and mortality in the community [15-20].^ Methods: The literature search was conducted using the University of Texas Health Science Center at Houston (UTHSC) and University of Texas Southwestern Medical Center (UTSW) online library. The key search terms used are “vitamin D deficiency And prevalence Or epidemiology”, “vitamin D deficiency And implication And public health” using PubMed and Mesh database and “vitamin D deficiency” using systematic reviews. The search is limited to Humans and the English language. The articles considered for the review are limited to Healthy US population to avoid health conditions that predispose the population to vitamin D deficiency. Only US population is considered to narrow down the study.^ Results: There is an increased prevalence of low levels of Vitamin D levels below the normal range in the US population regardless of age and health status. Vitamin D deficiency is also associated with increased risk of chronic illnesses and fatal cancers.^ Conclusion: This increased prevalence and the association of the deficiency with increased all-cause mortality has increased the economic burden and compromised the quality of life among the population. This necessitates the health care providers to routinely screen their patients for the Vitamin D status and counsel them to avoid the harmful effects of the Vitamin D deficiency. ^

THE EFFECTS OF STREPTOZOTOCIN DIABETES AND DIETARY IRON INTAKE ON CATALASE, GLUTATHIONE PEROXIDASE, SUPEROXIDE DISMUTASE AND LIPID PEROXIDATION IN CARDIAC AND SKELETAL MUSCLES OF RATS

Catalase, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) prevent oxygen free radical mediated tissue damage. Diabetes increases and a low dietary intake of iron decreases catalase activity in muscle. Therefore, the combined effects of diabetes and iron deficiency on the free radical scavenging enzyme system and lipid peroxidation were studied. Male, weanling rats were injected with streptozotocin (65 mg/kg, IV) and fed diets containing either 35 ppm iron (Db + Fe) or 8 ppm iron (Db $-$ Fe). Sham injected animals served as iron adequate (C + Fe) or iron deficient (C $-$ Fe) controls. Heart, gastrocnemius (GT), soleus and tibialis anterior (TA) muscles were dissected, weighted and analyzed for catalase, GSH-Px and SOD activities after 3, 6 or 9 weeks on the respective diets. The TBA assay was used to assess lipid peroxidation in the GT muscle. Diabetes elevated catalase activity in all muscles while it had a slight lowering effect on SOD and GSH-Px activities in the GT and TA muscles. In the C $-$ Fe rats, catalase activity declined and remained depressed in all muscles except the heart. There was an elevation in GSH-Px and SOD in the GT muscles of these animals after 6 weeks but not after 9 weeks of consuming the low iron diet. The Db $-$ Fe animals were unable to respond to the diabetic state with catalase activity as high as observed in the Db + Fe rats. Treatment with insulin or iron returned catalase to control levels. The C $-$ Fe animals had significantly lower levels of lipid peroxidation than the other groups at 6 and 9 weeks. Refeeding an iron adequate diet resulted in an increase in lipid peroxidation levels. These studies indicate that skeletal muscle free radical scavenging enzymes are sensitive to metabolic states and that dietary iron influences lipid peroxidation in this tissue. ^

Knowledge of exercise recommendations and energy intake from foods and beverages in relation to exercise behaviors within two Hispanic border communities

This research is a secondary analysis of the Qué Sabrosa Vida population-based cross-sectional study of two predominately Mexican American communities located along the Texas-Mexico border in 2000. There were two aims for this research. The first was to determine the relationship between knowledge of exercise and water recommendations, and exercise behavior and water consumption. The second was to determine the relationship between exercise behavior and percentage of energy consumption from beverages. Chi-square analysis revealed the majority of both populations had adequate knowledge about water and exercise recommendations, although significant percentages of the populations (>40%) did not consume water or exercise in adequate amounts. Knowledge was found to be a component of both behaviors, as it was more prevalent in the adults who exercised and consumed water in adequate amounts. Analysis of variance revealed no significant difference between overall beverage calorie percentage and exercise level (all p-values > 0.05); both regions and genders reported ∼18% of total caloric intake from beverages. There was no disproportionate influence of beverage calories on total caloric intake, after controlling for water consumption and independent of exercise behavior. These findings suggest that overall caloric intake, from both foods and beverages, may be the most influential factor to the energy imbalance contributing to the obesity crisis in these Hispanic border populations. ^