Active clinical trials for "Vitamin D Deficiency"

Many older adults do not get enough zinc, vitamin C and vitamin D, and this can be related to decreased ability to fight infection. The purpose of this research study is to determine if taking a multivitamin/mineral supplement every day for 12 weeks will increase the ability of immune cells in blood to kill bacteria.

Somali migrant women, often in veiled clothing, living in a town in mid Sweden on the 60:th parallel were observed to be weak and to have a waddling gate. Study 1 was carried out in the setting of an antenatal clinic administered from a primary care center in Borlänge, a Swedish middle-sized industrial town at the 60:th parallel in Sweden. The investigators chose an initial study period in late spring to reflect the effects of the dark season with little ultraviolet B radiation that affects vitamin D production. Study 1 was carried out in a short period of time. The recruitment was performed in a retrospective design in order to neglect the seasonal effects of ultraviolet B radiation. Study 1 was carried out in year 2010. It was a cross sectional baseline study of blood levels of vitamin D measured as 25-hydroxyvitamin D (25-OHD) and physical performance in 123 pregnant and new mothers from Somalia (n=52) and Sweden (n=71). Study 2: Examines the results on muscular performance, i.e. grip strength and squatting ability, from intervention with advice and prescription of vitamin D3 and calcium for 10 months, in all the women from study 1 with 25-OHD levels <50 nmol/L or 50 nmol/L of 25-OHD. Study 3: The recruitment to Study 1 also serves as recruitment for a cohort study on delivery outcome in birth protocols starting 2016. Study 4: The aim is to study the emic perspective and lifestyle related to vitamin D and strength in the group of Somali women by focus interviews among the Somali women from above. A possible fifth study will explore correlations between 25-OHD and pain distribution and pain parameters.

A double-blind randomized, placebo-controlled trial comparing the impact of 600 IU, 2000 IU, or 4000 IU of Vitamin D3 on third trimester 25(OH)D levels and change from baseline. The Vitamin D will be integrated in a standard prenatal vitamin, which will be taken from 12-16 weeks' gestation and continue throughout pregnancy. Umbilical cord 25(OH)D levels will also be determined. The investigators will generate preliminary data regarding Vitamin D intake and hypertensive disorders, blood pressure, and arterial function measured by tonography. The investigators will independently test blood pressure and proteinuria to identify preeclampsia cases.

This is a small pilot aerobic training trial designed to examine differences between normal-high and low vitamin D levels and 7-days of aerobic training on local VO2 measured by non-invasive Hybrid Diffuse Optical Spectroscopy.

While there have been a considerable number of studies on the impact of additional vitamin D in the diets of hens on the resulting egg vitamin D content, the effect of consumption of such vitamin D-enhanced eggs on vitamin D status of healthy human subjects has not been tested in a RCT.

This is a feasibility study to examine the treatment with Metformin, vitamin D with calcium supplement for insulin resistance in obese, black, female teens. The association of low vitamin D levels and decreased insulin sensitivity has been established. Thus, the specific aims of this study are: Specific aim 1: To examine the effect of an 8-week treatment with vitamin D and calcium supplementations on diabetes-related risk factors in obese, black, female teens. Hypothesis 1a: In obese, black, female teens with both insulin resistance and vitamin D deficiency, treatment with vitamin D and calcium supplementation will significantly improve measures of insulin resistance and sensitivity (as determined by the homeostatic model assessment for insulin resistance and whole body insulin sensitivity index measures) when compared to controls not receiving vitamin D and calcium. Hypothesis 1b: In obese, black teen females with both insulin resistance and vitamin D deficiency, treatment with vitamin D and calcium supplementation will significantly improve measures of cardiovascular disease (decreased BMI and improved triglycerides and LDL) when compared to controls not receiving vitamin D and calcium. Specific aim 2: To determine if the addition of Metformin to the 8-week treatment with vitamin D and calcium supplementations improves diabetes-related risk factors in obese, black, female teens. Hypothesis 2a: In obese, black, female teens with both insulin resistance and vitamin D deficiency, treatment with Metformin, vitamin D, and calcium supplementation will significantly improve measures of insulin resistance and sensitivity (as determined by the homeostatic model assessment for insulin resistance and whole body insulin sensitivity index measures) when compared to standard of care or treatment with vitamin D with calcium supplementation alone while controlling for dietary intake of vitamin D and calcium. Hypothesis 2b: In obese, black, female teens with both insulin resistance and vitamin D deficiency, treatment with Metformin, vitamin D, and calcium supplementation will significantly improve measures of cardiovascular disease risk (as determined by the decreased BMI, improved triglycerides and LDL) when compared to standard of care or treatment with vitamin D with calcium supplementation alone while controlling for dietary intake of vitamin D and calcium.

The purpose of this study is to determine the capability to absorb calcium as a measure of the sufficient levels of Vitamin D. Calcium absorption will be measured at baseline and after vitamin D3, by dual calcium isotope technique using stable isotopes in post menopausal women between the ages 50 and 70yrs. Subjects will have a screening visit, first and final visits. Subjects will be randomly assigned to a placebo or daily doses of vitamin D3. The specific aim of this study is to determine the level of vitamin D that will maximize the absorption of calcium and establish the relationship between the administered calcium dose and the actual absorbed calcium dose versus administered dose of Vitamin D and the serum levels of Vitamin D.

The purpose of this research is to determine what supplemental doses of vitamin D may be necessary to raise serum levels to optimal levels and how vitamin D supplementation and changes in vitamin D status impact cardiovascular risk factors in schoolchildren.

The purpose of this study is to compare the effects of two different forms of vitamin D supplements (vitamin D3 and 25-hyrdroxyvitamin D3 [25(OH)D3]) on vitamin D levels in the blood, and on markers of skeletal and immune health. This study is designed as a pilot study. A multi-ethnic cohort of 48 patients will be included (12 Caucasian, 12 African American, 12 Hispanic/Latino, 12 Asian/Asian American). Potential study candidates will undergo a screening visit during which a medical history will be taken, a physical exam performed, a dietary questionnaire administered, and blood collected. The purpose of the screening visit is to identify vitamin D-deficient (25-hydroxyvitamin D <20 ng/ml) individuals who are candidates for vitamin D supplementation. Eligible patients will then be randomly assigned to receive either vitamin D3 (2400 IU/day) or 25(OH)D3 (20 mcg/day) for 16 weeks. After initiating supplementation, study patients will return for follow-up visits at weeks 4, 8, and 16. At each visit, blood will be collected to assess vitamin D levels in the blood, as well as markers of skeletal and immune function. Participation in this study will therefore involve a total of 5 visits (1 screening visit, 1 randomization visit during which participants will receive their study supplements, 3 follow-up visits). After all data is collected, changes in vitamin D levels in the blood following supplementation with either vitamin D3 versus 25(OH)D3 will be determined, and correlated to markers of calcium balance and immune function. Knowledge gained from this study may have a significant impact on how vitamin D status is defined, and how vitamin D repletion is administered.

Vitamin D is a natural nutrient. A little comes from our normal daily diet. Most of it comes from our skin after we have been in sunlight. If we have darker skin, we make less vitamin D. Vitamin D balances the calcium in our body. If our vitamin D levels get too low, it can cause health problems. It may increase our chance of getting high blood pressure or diabetes. Another problem we may have if our vitamin D levels are low is that our blood vessels may not work normally. These are important health problems for anyone. Because African Americans have darker skin, they are more likely than most other racial/ethnic groups to have low vitamin D levels. This study will look at treating African Americans with low vitamin D levels. The goal of this study is to see how vitamin D helps blood vessels work. The investigators will do this study in African Americans who are overweight, have high blood pressure and have low vitamin D levels. The investigators will see if getting the vitamin D level to a normal value will improve how blood vessels work. The dose of vitamin D that will be given in this study is a high dose that is given to people with low vitamin D levels.