Clinical practice guidelines for vitamin D in the United Arab Emirates

© 2016 Elsevier Ltd In the UAE and the Gulf region in general, there are several intricate public health issues in the context of vitamin D deficiency that needs to be addressed. Changes in lifestyle such as diet, lack of exercise, cultural habits, avoiding sun exposure due to excessive heat, and other risk factors predispose those who live in GULF countries, such as Emiratis likely to becoming vitamin D deficient. Consequently, the prevalence of vitamin D deficiency is high, and new guidelines are needed to overcome this major public health issue. Peer-reviewed papers related to guidelines and those vitamin D-related papers relevant to the Middle-Eastern region were extracted from multiple research databases using key words according to the general guidelines from the Preferred Reporting Items for Systematic Analysis. This guideline was prepared focusing on the United Arab Emirate and the Gulf populations, to overcome the high incidence of vitamin D deficiency and to improve overall health. We recommend the following vitamin D supplementations for different groups of people: (A) Breastfed infants supplement with 400 IU/day up to age 6 months, and 400–600 IU/day between 6 and 12 months, depending on daily intake of total vitamin D and sun exposure; (B) for children and adolescents of age 1–18 years supplement with 600–1000 IU/day depending on the body weight; (C) adults greater than 18 years’, supplementation with 1000–2000 IU/day is recommended, while, (D) the elderly (over 65 years) should be supplemented with 2000 IU/day, throughout the year; (E) pregnant and breast feed women, 2000 IU/day from the first trimester of pregnancy. (F) Premature infants, supplementation of 400–800 IU/daystart from the first days of life. (G) For obese, individuals and those with metabolic syndrome, supplementation of 2000 IU/day (H) For individuals with dark skin complexions and for night workers, supplementation of 1000–2000 IU/day (25–50 μg/day), throughout the year, depending on body weight. The goal of supplementation is to achieve and longer term maintenance of serum 25(OH)D concentration of 30–50 ng/mL

High prevalence of vitamin D deficiency in Cambodian women:A common deficiency in a sunny country

Recent studies have shown that in spite of being generally close to the equator; vitamin D deficiency is common in South East Asian countries. In order to quantify micronutrient status for women and children in Cambodia; a nationally-representative survey was conducted in 2014 linked to the Cambodian Demographic Health Survey. The countrywide median of 25(OH) D was, respectively, 64.9 and 91.1 nmol/L for mothers and children. Based on The Endocrine Society cutoffs (>50<75 nmol/L = insufficiency; <= 50 nmol/L = deficiency); 64.6% of mothers and 34.8% of their children had plasma vitamin D concentrations indicating insufficiency or deficiency. For deficiency alone, 29% of the mothers were found to be vitamin D deficient, but only 13.4% of children. Children who live in urban areas had a 43% higher rate of vitamin D insufficiency versus those who live in rural areas (OR; 1.434; 95% CI: 1.007; 2.041). However, such differences were not observed in their mothers. The high prevalence of vitamin D deficiency is likely in part due to lifestyle choices, including sun avoidance, increasingly predominant indoor work, and covered transport. These survey findings support the need for a broader national Cambodian study incorporating testing of adult men, adolescents and the elderly, and encompassing other parameters such as skeletal health. However, the data presented in this study already show significant deficiencies which need to be addressed and we discuss the benefit of establishing nationally-mandated food fortification programs to enhance the intake of vitamin D

Vitamin D deficiency prevalence and predictors in early pregnancy among Arab women

Data regarding the prevalence and predictors of vitamin D deficiency during early pregnancy are limited. This study aims to fill this gap. A total of 578 Saudi women in their 1st trimester of pregnancy were recruited between January 2014 and December 2015 from three tertiary care antenatal clinics in Riyadh, Saudi Arabia. Information collected includes socio-economic, anthropometric, and biochemical data, including serum vitamin D (25(OH)D) levels, intake of calcium and vitamin D, physical activity, and sun exposure indices. Pregnant women with 25(OH)D levels 3.5), low HDL-cholesterol, and living in West Riyadh were significant independent predictors for vitamin D deficiency, with odds ratios (ORs) (95% confidence interval) of 25.4 (5.5–117.3), 17.8 (2.3–138.5), 4.0 (1.7–9.5), 3.3 (1.4–7.9), 2.8 (1.2–6.4), and 2.0 (1.1–3.5), respectively. Factors like increased physical activity, sun exposure at noon, sunrise or sunset, high educational status, and residence in North Riyadh were protective against vitamin D deficiency with ORs 0.2 (0.1–0.5); 0.2 (0.1–0.6); 0.3 (0.1–0.9); and 0.4 (0.2–0.8), respectively. All ORs were adjusted for age, BMI, sun exposure, parity, summer season, vitamin D intake, multivitamin intake, physical activity, education, employment, living in the north, and coverage with clothing. In conclusion, the prevalence of vitamin D deficiency among Saudi women during early pregnancy was high (81%). Timely detection and appropriate supplementation with adequate amounts of vitamin D should reduce the risks of vitamin D deficiency and its complications during pregnancy

Modeling of biological doses and mechanical effects on bone transduction

Shear stress, hormones like parathyroid and mineral elements like calcium mediate the amplitude of stimulus signal which affects the rate of bone remodeling. The current study investigates the theoretical effects of different metabolic doses in stimulus signal level on bone. The model was built considering the osteocyte as the sensing center mediated by coupled mechanical shear stress and some biological factors. The proposed enhanced model was developed based on previously published works dealing with different aspects of bone transduction. It describes the effects of physiological doses variations of Calcium, Parathyroid Hormone, Nitric Oxide and Prostaglandin E2 on the stimulus level sensed by osteocytes in response to applied shear stress generated by interstitial fluid flow. We retained the metabolic factors (Parathyroid Hormone, Nitric Oxide, and Prostaglandin E2) as parameters of bone cell mechanosensitivity because stimulation/inhibition of induced pathways stimulates osteogenic response in vivo. We then tested the model response in term of stimulus signal variation versus the biological factors doses to external mechanical stimuli. Despite the limitations of the model, it is consistent and has physiological bases. Biological inputs are histologically measurable. This makes the model amenable to experimental verification

Effect of CGRP and sumatriptan on the BOLD response in visual cortex

To test the hypothesis that calcitonin gene-related peptide (CGRP) modulates brain activity, we investigated the effect of intravenous CGRP on brain activity in response to a visual stimulus. In addition, we examined if possible alteration in brain activity was reversed by the anti-migraine drug sumatriptan. Eighteen healthy volunteers were randomly allocated to receive CGRP infusion (1.5 μg/min for 20 min) or placebo. In vivo activity in the visual cortex was recorded before, during and after infusion and after 6 mg subcutaneous sumatriptan by functional magnetic resonance imaging (3 T). 77% of the participants reported headache after CGRP. We found no changes in brain activity after CGRP (P = 0.12) or after placebo (P = 0.41). Sumatriptan did not affect brain activity after CGRP (P = 0.71) or after placebo (P = 0.98). Systemic CGRP or sumatriptan has no direct effects on the BOLD activity in visual cortex. This suggests that in healthy volunteers both CGRP and sumatriptan may exert their actions outside of the blood–brain barrier