Fuente: Medscape, Becky McCall, 17-05-2020
En la última semana se han publicado varios informes especulando si la vitamina D reduce la gravedad de la infección por COVID-19.
Fuente: Medscape, Becky McCall, 17-05-2020
En la última semana se han publicado varios informes especulando si la vitamina D reduce la gravedad de la infección por COVID-19.
Una ingesta excesiva de vitamina D podría alterar negativamente a la salud en la adolescencia – correofarmacéutico.com
Varios estudios observacionales también han apuntado vínculos entre las deficiencias de la vitamina D y un gran peso asociado a complicaciones médicas, incluyendo enfermedades cardiovasculares y resistencia a la insulina. Otros estudios previos demostraron una relación entre la vitamina D en sangre y la mejora en la función vascular. Como resultado, padres, cuidadores y proveedores de salud a menudo suministran altas dosis de suplementación, tanto en niños como adolescentes, en un intento de disminuir o revertir alguna de las complicaciones asociadas a la obesidad.
“Me ha sorprendido que no hemos encontrado más beneficios de salud”, dijo Kumar. “no estamos diciendo que los suplementos con vitamina D sean malos a dosis razonables, y sabemos que la mayoría de los obesos adolescentes tienen deficiencia en vitamina D. Solo estamos diciendo que no está comprobada su utilidad para mejorar la salud en adolescentes”.
Este es el primer estudio en el que Kumar informa del aumento de colesterol y triglicéridos durante la suplementación con vitamina D, un hallazgo, dice, que podría ser atribuido al menor número de niños que participaron en el estudio y a un periodo relativamente corto de tiempo.
La investigadora decidió estudiar la vitamina D en adolescentes con sobrepeso porque esta población tiene un riesgo elevado de enfermedad crónica, y por la creciente popularidad de los compuestos homeopáticos o tratamientos complementarios para la obesidad. Apuntó que la hipervitaminosis de vitamina D provoca poco apetito, náuseas, vómitos y complicaciones renales.
August 04, 2015Postmenopausal women who took vitamin D supplements to a level of 30 ng/mL increased calcium absorption, but that did not translate into benefits in bone density, muscle function, muscle mass, or falls in a single-center, randomized, double-blind, placebo-controlled trial. Low doses of vitamin D supplementation gave outcomes equivalent to placebo.
Karen E. Hansen, MD, from the Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, and colleagues published their findings online August 3 in JAMA Internal Medicine.
“It is possible that treatment beyond 1 year would result in better outcomes, but these data provide no support for use of higher-dose cholecalciferol replacement therapy or indeed any dose of cholecalciferol compared with placebo,” Deborah Grady, MD, MPH, from the Department of Epidemiology at the University of California, San Francisco, writes in an accompanying editorial.
The low-dose regimen consisted of 800 IU vitamin D per day, and the high-dose regimen was 50,000 IU twice monthly. Women in the high-dose group received extra doses as needed to keep their serum 25-hydroxyvitamin D levels above 30 ng/mL, the level currently recommended by some researchers. (The Institute of Medicine recommends 20 ng/mL.)
The investigators enrolled 230 postmenopausal women with 25-hydroxyvitamin D levels ranging from 14 to 27 ng/mL and counseled them to consume between 600 and 1400 mg calcium per day, an amount typical of postmenopausal American women. The study excluded women older than 75 years because age is associated with intestinal resistance to vitamin D. The researchers also excluded women with certain intestinal disorders, diabetes, or fractures or who had taken bone-active medications. The researchers stratified participants by parathyroid hormone level and calcium intake and gave the women sunscreen to use in summer months.
After 1 year, calcium absorption, the primary outcome, increased by 1% in women who received the higher dose, but decreased by 2% in those who received the low dose and 1.3% in those who received placebo.
There was no difference among the three groups in bone mineral density (adjusted P = .12), timed up-and-go and sit-to-stand tests, muscle mass, number of falls, health assessment questionnaire score, or fractures.
The investigators note that few participants were black, and the results are not generalizable to men, young adults, or women older than 75 years.
“We found no data to support experts’ recommendations to maintain serum 25(OH)D levels of 30 ng/mL or higher in postmenopausal women,” the authors conclude.
One author reported working as a local principal investigator for a Takeda clinical trial. The other authors and Dr Grady have disclosed no relevant financial relationships.
JAMA Intern Med. Published online August 3, 2015. Article abstract, Editorial extract
Los niveles bajos de vitamina D en menores elevarían el riesgo de enfermedad cardiovascular – correofarmacéutico.com
“Los niveles de vitamina D sérica observados en este colectivo son similares a los encontrados en otros escolares españoles y de otros países. Esto confirma que la deficiencia en vitamina D es un problema prevalente en niños y adolescentes”, han subrayado los autores.
La vitamina D se adquiere a través de los alimentos como, por ejemplo, el pescado azul, la yema de huevo o los productos lácteos. Por ello, los investigadores achacan “gran parte” de las carencias de vitamina D presentadas por los menores a una dieta inadecuada.
Pero también, esta vitamina se adquiere de la propia síntesis que realiza el organismo con la luz solar aunque, tal y como ha advertido la investigadora de la Facultad de Farmacia de la UCM y autora principal de la investigación, Ana María López-Sobaler, la latitud de España “no es la óptima” y en los meses de invierno la inclinación de la Tierra “no es la más favorable” para la síntesis de la vitamina D. “Incluso en los meses de verano, los valores siguen siendo insuficientes”, ha concluido.
October 22, 2014Drinking milk produced from sources other than cows may increase the risk for low levels of serum vitamin D in young children compared with drinking cow’s milk, according to a study published online October 20 in the Canadian Medical Association Journal.
Although fortification of cow’s milk with vitamin D is required in the United States and Canada, fortification of non-cow’s milk is voluntary.
Grace J. Lee, BASc, from the University of Toronto, Ontario, Canada, and colleagues conducted a cross-sectional study of children between 1 and 6 years old recruited from seven pediatric or family medicine primary care practices during well-child visits between December 2008 and September 2013. The practices are in the network collaboration of the Faculty of Medicine, the Department of Paediatrics, and the Department of Family and Community Medicine at the University of Toronto.
The researchers compared levels of serum 25-hydroxyvitamin D in 2468 children who drink cow’s milk with levels in 363 children who drink goat’s milk or plant-based milk. Researchers collected data through physical measurements, blood samples, and interviews with parents.
Mean age of participants was 2.9 years, and the children were split almost equally between boys and girls.
The median vitamin D level was 80 nmol/L in the entire study population, 81 nmol/L in those drinking just cow’s milk (n = 1950), and 78 nmol/L in those drinking only non-cow’s milk (n = 146).
However, the vitamin D level was below 50 nmol/L in 4.7% of those who drank only cow’s milk and in 11.0% of those who drank only non-cow’s milk. Using logistic regression analysis, the researchers found that children who drank only non-cow’s milk were almost three times as likely as children who drank cow’s milk to have vitamin D levels lower than 50 nmol/L (odds ratio, 2.7; 95% confidence interval, 1.6 – 4.7).
Overall, in an unadjusted analysis, researchers found that a 3.1% decrease (P = .005) in vitamin D level occurred for each 250-mL cup of non-cow’s milk consumed.
“Among children who drank both types of milk, each additional cup of non–cow’s milk beverage consumed was associated with a 5% decrease in 25-hydroxyvitamin D level,” the researchers write. The estimated was adjusted for clinically relevant variables, the authors note.
They conclude, “Our findings may be helpful for health care providers caring for children who drink non–cow’s milk beverages because of an allergy to cow’s milk, lactose intolerance or a dietary preference.”
The authors have disclosed no relevant financial relationships.
CMAJ. Published online October 20, 2014. Abstract
Hierro, Omega 3 DHA y vitamina D serían esenciales para el correcto desarrollo infantil – correofarmacéutico.com
CF | redaccion@correofarmaceutico.com
| 18/03/2015 15:07
Hierro, Omega 3 DHA y vitamina D serían esenciales para el correcto desarrollo infantil – correofarmacéutico.com
La deficiencia de vitamina D está más vinculada a la diabetes que a la obesidad – DiarioMedico.com
January 05, 2015
Are there particular populations of adults for whom you would recommend screening, or vitamin D supplementation in the absence of screening?
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Response from David B. Reuben, MD Professor and Archstone Foundation Endowed Chair, Department of Medicine, University of California Los Angeles; Chief, Division of Geriatrics, UCLA Medical Center, Santa Monica, California |
Several prospective epidemiologic studies have shown associations of low serum vitamin D levels with lower global cognition and more rapid functional decline,[1-4] as well as the development of dementia and Alzheimer disease.[5] In a recent review of nine epidemiologic studies, the serum level that was associated with worse cognitive health was found to be around 10 ng/mL.[1] However, such studies cannot determine whether low vitamin D was causal or whether persons with memory problems were less likely to leave their homes and therefore have less sun exposure, leading to lower vitamin levels.
It is less clear whether and how much vitamin D supplementation would improve cognition or prevent decline in older populations. To date, there are no randomized clinical trial data supporting supplementation for improving cognition or preventing decline.
In the Women’s Health Initiative Memory Study, calcium and 400 IU vitamin D3 supplements given to a randomized sample of women did not result in differences in performance (attention, working memory, word knowledge, spatial ability, verbal fluency, verbal memory, figural memory, or fine motor speed) over 7.8 years.[6] Moreover, in observational studies, high levels of 25-hydroxyvitamin D, especially among those taking vitamin D supplements, have been associated with cognitive impairment on a battery of attention tests, suggesting a possible U-shaped curve relationship.[7]
Recently, the US Preventive Services Task Force has reviewed the evidence for screening for vitamin D deficiency and concluded that the current evidence is “insufficient to assess the balance of benefits and harms of screening for vitamin D deficiency in asymptomatic adults.”[8] Part of the rationale for this recommendation stemmed from the paucity of studies that used an internationally recognized reference standard and the lack of consensus on the laboratory values that define vitamin D deficiency.
In summary, the best evidence supports the recommendation of daily dietary vitamin D intake of 600 IU in adults aged 18-70 years and 800 IU in adults older than 70 years (1000 IU is commonly marketed).[9] Vitamin D levels should be obtained in patients with symptoms of osteomalacia (eg, diffuse bone and joint pain, fractures, muscle weakness, and difficulty walking), especially in malabsorption states, and before starting intravenous bisphosphonate therapy for osteoporosis because of the potential for precipitating hypocalcemia in patients with hypovitaminosis D receiving these medications. Currently, there is no indication for screening asymptomatic patients for vitamin D levels for the purpose of potentially supplementing with vitamin D in order to prevent changes in cognitive outcomes.
Developed in association with the UCLA Alzheimer’s and Dementia Care Program.
January 05, 2015
Are there particular populations of adults for whom you would recommend screening, or vitamin D supplementation in the absence of screening?
![]() |
Response from David B. Reuben, MD Professor and Archstone Foundation Endowed Chair, Department of Medicine, University of California Los Angeles; Chief, Division of Geriatrics, UCLA Medical Center, Santa Monica, California |
Several prospective epidemiologic studies have shown associations of low serum vitamin D levels with lower global cognition and more rapid functional decline,[1-4] as well as the development of dementia and Alzheimer disease.[5] In a recent review of nine epidemiologic studies, the serum level that was associated with worse cognitive health was found to be around 10 ng/mL.[1] However, such studies cannot determine whether low vitamin D was causal or whether persons with memory problems were less likely to leave their homes and therefore have less sun exposure, leading to lower vitamin levels.
It is less clear whether and how much vitamin D supplementation would improve cognition or prevent decline in older populations. To date, there are no randomized clinical trial data supporting supplementation for improving cognition or preventing decline.
In the Women’s Health Initiative Memory Study, calcium and 400 IU vitamin D3 supplements given to a randomized sample of women did not result in differences in performance (attention, working memory, word knowledge, spatial ability, verbal fluency, verbal memory, figural memory, or fine motor speed) over 7.8 years.[6] Moreover, in observational studies, high levels of 25-hydroxyvitamin D, especially among those taking vitamin D supplements, have been associated with cognitive impairment on a battery of attention tests, suggesting a possible U-shaped curve relationship.[7]
Recently, the US Preventive Services Task Force has reviewed the evidence for screening for vitamin D deficiency and concluded that the current evidence is “insufficient to assess the balance of benefits and harms of screening for vitamin D deficiency in asymptomatic adults.”[8] Part of the rationale for this recommendation stemmed from the paucity of studies that used an internationally recognized reference standard and the lack of consensus on the laboratory values that define vitamin D deficiency.
In summary, the best evidence supports the recommendation of daily dietary vitamin D intake of 600 IU in adults aged 18-70 years and 800 IU in adults older than 70 years (1000 IU is commonly marketed).[9] Vitamin D levels should be obtained in patients with symptoms of osteomalacia (eg, diffuse bone and joint pain, fractures, muscle weakness, and difficulty walking), especially in malabsorption states, and before starting intravenous bisphosphonate therapy for osteoporosis because of the potential for precipitating hypocalcemia in patients with hypovitaminosis D receiving these medications. Currently, there is no indication for screening asymptomatic patients for vitamin D levels for the purpose of potentially supplementing with vitamin D in order to prevent changes in cognitive outcomes.
Developed in association with the UCLA Alzheimer’s and Dementia Care Program.
Vitamin D supplementation prevented moderate to severe exacerbations of chronic obstructive pulmonary disease (COPD) in patients with vitamin D deficiency in a multicenter, double-blind, randomized controlled trial. The results were published online December 2 in the Lancet.
“Contrary to expectation, we did not find evidence that vitamin D3 prevented upper respiratory infections, either in the study population as a whole or in the subgroup of participants with lower baseline vitamin D status,” write Adrian Martineau, PhD, from the Barts and London School of Medicine and Dentistry at Queen Mary University of London, United Kingdom. The supplements also did not affect the primary endpoint, which was time to first upper respiratory infection or moderate or severe exacerbation.
The vitamin was given in bolus doses of 3 mg (120,000 IU) six times over the course of a year. The study included 122 patients in the treatment group, all of whom received at least one dose of vitamin D, and 94 completed the study protocol. The control group included 118 patients, 85 of whom completed the study protocol. Patient characteristics were similar between groups, including the fact that 87%, in total, had a vitamin D deficiency, defined as serum 25-hydroxyvitamin D levels less than 75 nmol/L, at baseline.
Treatment did not affect the median time to first moderate or severe COPD exacerbation (adjusted hazard ratio [AHR] 0.86; 95% confidence interval [CI], 0.60 – 1.24; P = .42) or time to first upper respiratory infection (AHR, 0.95; 95% CI, 0.69 – 1.31; P = .75). The researchers defined exacerbations as moderate if they were treated with systemic steroids or antibiotics but did not result in a visit to the emergency room; those that did were classified as severe.
The investigators considered whether baseline vitamin D deficiency affected the time to exacerbation or infection and found that patients with baseline levels of less than 50 nmol/L had a reduced risk for moderate or severe exacerbation (AHR, 0.57; 95% CI, 0.35 – 0.92; P = .021) with vitamin D administration.
The authors had conducted a previous trial on patients with less severe COPD, in which they found that supplementation was helpful for patients with deficiency at baseline but had the opposite effect in those with higher levels. They write, “Taken together, findings from these two trials suggest that vitamin D supplementation should be offered to COPD patients with lower vitamin D status to reduce the risk of moderate or severe exacerbation.”
The authors have disclosed no relevant financial relationships.
Lancet. Published online December 2, 2014. Abstract