Online Library: Vitamin D
The following pages provide an overview of the most recent research and clinical studies about the health benefits of vitamin D. This collection of scientific facts proves that anyone who privately or publicly questions the health value of micronutrients does not serve YOUR health, or the health of the people, but rather the multi-billion dollar investment 'business with disease' based on patented pharmaceutical drugs.
We encourage you to forward the link to this important online library on natural health – one of the largest ones in the world – to your friends. You may also print out the articles you find most important for your own health condition and share them with your doctor. Any responsibly acting health professional will be grateful to receive such science-based health education.
Decreased bioavailability of vitamin D in obesity
Source: The American journal of clinical nutrition 2000; 72(3):690-3
Affiliation: Southern Illinois University School of Medicine, Springfield, USA.
Abstract: Obesity is associated with vitamin D insufficiency and secondary hyperparathyroidism. This study assessed whether obesity alters the cutaneous production of vitamin D(3) (cholecalciferol) or the intestinal absorption of vitamin D(2) (ergocalciferol). Healthy, white, obese [body mass index (BMI; in kg/m(2)) > or = 30] and matched lean control subjects (BMI = 25) received either whole-body ultraviolet radiation or a pharmacologic dose of vitamin D(2) orally. Obese subjects had significantly lower basal 25-hydroxyvitamin D concentrations and higher parathyroid hormone concentrations than did age-matched control subjects. Evaluation of blood vitamin D(3) concentrations 24 h after whole-body irradiation showed that the incremental increase in vitamin D(3) was 57% lower in obese than in non obese subjects. The content of the vitamin D(3) precursor 7-dehydrocholesterol in the skin of obese and non obese subjects did not differ significantly between groups nor did its conversion to previtamin D(3) after irradiation in vitro. The obese and non obese subjects received an oral dose of 50000 IU (1.25 mg) vitamin D(2). BMI was inversely correlated with serum vitamin D(3) concentrations after irradiation and with peak serum vitamin D(2) concentrations after vitamin D(2) intake. Conclusions: Obesity-associated vitamin D insufficiency is likely due to the decreased bioavailability of vitamin D(3) from cutaneous and dietary sources because of its deposition in body fat compartments.
Vitamin D Deficiency in Obese Children and Its Relationship to Glucose Homeostasis
Source: Journal of Clinical Endocrinology & Metabolism November 2011 jc.2011-1507
Affiliation: Departments of Pediatrics and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.
Abstract: The aim of the study was to compare the prevalence of vitamin D deficiency in obese and non-overweight children in North Texas, to examine relationships between dietary habits and 25-hydroxyvitamin D [25(OH)D] level in obese children, and to examine the relationship between 25(OH)D level and markers of abnormal glucose metabolism and blood pressure. Using a cross-sectional design, systolic and diastolic blood pressure, dietary information, serum 25(OH)D, fasting glucose and insulin, 2-h glucose from oral glucose tolerance test, hemoglobin A1c (HbA1c), and homeostasis model assessment of insulin resistance were recorded for 411 obese subjects (6–16 yr old) at an obesity referral clinic. 25(OH)D was also obtained from 87 control non-overweight subjects (6–16 yr old). Ninety-two percent of obese subjects had a 25(OH)D level below 75 nmol/liter, and 50% were below 50 nmol/liter. Among non-overweight subjects, these frequencies were 68 and 22%, respectively. 25(OH)D was negatively associated with soda intake, juice intake, and skipping breakfast. 25(OH)D was negatively correlated with homeostasis model assessment of insulin resistance and 2-h glucose after adjustment for body mass index and age but was not correlated with hemoglobin A1c, systolic blood pressure Z score*, or diastolic blood pressure Z score. Conclusions: Vitamin D deficiency is common in children in this southern United States location and is significantly more prevalent in obese children. Lower 25(OH)D level is associated with risk factors for type 2 diabetes in obese children.
* A Z-Score is a statistical measure. A Z-Score tells how a single data point compares to normal data. A Z-Score says not only whether a point was above or below average, but how unusual the measurement is.
An exploratory study of postpartum depression and vitamin D
Source: Journal of the American Psychiatric Nurses Association 2010 May; 16(3):170-7
Affiliation: Medical University of South Carolina, Charleston, USA.
Abstract: Low levels of serum 25-hydroxyvitamin D (25[OH]D), a reliable measurement of vitamin D, have been implicated in several mood disorders. To date, studies exploring the relationship between vitamin D and postpartum depression are absent from the literature. To determine whether a relationship exists between symptoms associated with postpartum depression and vitamin D levels and to determine if serum 25(OH) D levels can predict the incidence of symptoms associated with postpartum depression. An exploratory, descriptive study was conducted, using a convenience sample of 97 postpartum women attending seven monthly visits. Women provided serum 25(OH)D samples and completed the Edinburgh Postpartum Depression Scale (EPDS) at each visit. A significant relationship over time was found between low 25(OH)D levels and high EPDS scores, indicative of postpartum depression. Future rigorous studies investigating vitamin D and postpartum depression are warranted with larger sample sizes using confirmatory methods to diagnose postpartum depression.
Improvement of Primary Dysmenorrhea Caused by a Single Oral Dose of Vitamin D: Results of a Randomized, Double-blind, Placebo-Controlled Study
Source: Archives of internal medicine 2012;172(4):366-367
Affiliation: Dipartimento di Medicina Interna (Drs Lasco and Catalano), Sezione di Endocrinologia, Dip Clinico Sperimentale di Medicina e Farmacologia (Dr Benvenga), and Master di Endocrinologia dell’Infanzia, dell’ Adolescenza e della Donna (Dr Benvenga), Università di Messina, Messina, Italy; and Programma Interdisciplinare di Endocrinologia Molecolare Clinica e Salute Endocrina della Donna, Policlinico A.O.U. “G. Martino” (Dr Benvenga), Messina.
Abstract: Primary dysmenorrhea is a common disorder characterized by painful uterine cramping, just before or during menstruation, in the absence of any pelvic pathologic conditions. It is frequently accompanied by other symptoms such as nausea, vomiting, diarrhea, asthenia, and insomnia. Primary dysmenorrhea affects almost half of menstruating women, often resulting in school and work absenteeism with major educational and economic consequences. An excessive uterine production of prostaglandins (PGs) is the pathogenetic trigger of dysmenorrhea. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the currently accepted drugs for the management of this disorder. Because the vitamin D receptor is widespread and the mitochondrial cytochrome P450 enzyme 25-hydroxyvitamin D3 (25[OH]D)-1α-hydroxylase (1α-OHase), which catalyzes the synthesis of 1α,25-dihydroxyvitamin D3 (1,25[OH]2D) from its precursor 25(OH)D, is expressed in the human uterus and in immune system cells, and because vitamin D reduces the synthesis of PGs, a beneficial effect of vitamin D in the uterus pathophysiology is possible. The aim of this prospective intervention study was to evaluate the effect of a single-loading oral dose of cholecalciferol (300 000 IU) on primary dysmenorrhea.Forty women aged 18 to 40 years, attending the outpatient clinics of the Department of Internal Medicine of the University of Messina, Messina, Italy, for primary dysmenorrhea were enrolled. Patients were included if (1) their menstrual cycles lasted 21 to 35 days, with menstruation lasting 3 to 7 days; (2) they experienced at least 4 consecutive painful periods in the past 6 months with the pain starting one day before or on the day of onset of bleeding; (3) they showed a 25(OH)D serum level below the upper limit of the lowest quartile. Patients had to be in good health and taking no medications including calcium, vitamin D, and oral contraceptives. Use of NSAIDs was permitted and it had to be recorded in a sheet given to each woman.Women were randomized into 2 groups: 20 women received a single oral dose of cholecalciferol (300 000 IU/1 mL) 5 days before the putative beginning of their next menstrual cycle, while another 20 women received placebo.The primary outcome was the intensity of menstrual pain as measured by a visual analog scale. The secondary outcome was use of NSAIDs during the 2-month duration of the study. The 2 groups did not differ significantly in age, body mass index, severity of pain, and 25(OH)D levels at baseline. There was a negative correlation between the pain score at baseline and the levels of 25(OH)D (r = −0.36; P = .02). The authors observed a significant reduction of pain in the vitamin D group compared with the placebo group (P < .001) over the 2-month duration of the study. The greatest reduction of pain score was seen in women with severe pain at baseline in vitamin D group. The authors recorded no NSAID use in vitamin D group at 1 and 2 months, while 40% of women in placebo group took NSAIDs at least once.