What is vitamin D? Where does it come from?
Vitamin D is a fat-soluble vitamin that is produced in the body when the skin is exposed to sunlight. It is found in some foods such as oily fish, liver, and mushrooms, and is also available as a supplement.
The National Institutes of Health (NIH) recommends a daily intake of 15 μg (400 IU) of vitamin D for most adults, and 20 μg for people over 70 years of age. We recommend increasing it. These guidelines assume that people will be exposed to minimal sunlight.
Vitamin D plays many roles in the body, including promoting calcium absorption in the intestines to allow normal bone mineralization and growth, reducing inflammation, and regulating cell growth. .
Vitamin D, found in foods, supplements, and produced in the skin, must be metabolized before it can be used by the body. The first step occurs in the liver, where vitamin D is converted to a hydroxylated form called 25-hydroxyvitamin D (25(OH)D). 25(OH)D is further hydroxylated in the kidney to the bioactive form, 1,25-dihydroxyvitamin D.
Scarcity or scarcity?
Clinicians use the amount of 25(OH)D present in the blood as a marker of deficiency or deficiency.of NIH guidelines Other health organizations use different values, but define a deficiency as a serum 25(OH)D concentration of less than 12 ng/mL and a deficiency of less than 20 ng/mL.
“Vitamin D plays an important role in bone health, immune function, and the regulation of various metabolic processes. Recent research reveals surprising statistics. – Up to 42% of the population suffers from this deficiency,” said Dr. Kevin Huffman, a primary care physician and medical director of the Florida Injury Center.
Symptoms of vitamin D deficiency include muscle weakness, bone and muscle pain, and tingling in the hands and feet.
Research suggests that vitamin D deficiency is associated with loss of brain plasticity, worsening of symptoms of polycystic ovary syndrome, and, in pregnant women, increased risk of diabetes in children.
Vitamin D deficiency is associated with increased cancer mortality
“The relationship between vitamin D and carcinogenesis is complex. It includes a pivotal role in regulating cell proliferation, apoptosis (programmed cell death), as well as immune function,” Huffman said. Stated.
Recent research published in european cancer journal investigated the effect of vitamin D deficiency on mortality in 18 different cancer types and on overall cancer mortality. Researchers analyzed data from 411,436 people in the UK Biobank using cause-specific Cox regression models to adjust for other lifestyle and environmental factors that may influence the results. .
More than a third (34.4%) of participants were taking vitamin D insufficient and 21.1% had vitamin D deficiency.
The paper reported that vitamin D deficiency was associated with increased mortality from cancer overall and four specific cancers: stomach, colorectal, lung, and prostate. vitamin D shortage It was also associated with increased mortality from lung and prostate cancer.
The authors also investigated whether taking vitamin D or multivitamin supplements affected mortality and found that taking vitamin D supplements was associated with lower lung cancer mortality compared to participants who did not take supplements. and found that it was associated with lower overall cancer mortality. Multivitamin intake was associated with lower mortality from melanoma.
Although this study highlights the importance of adequate vitamin D intake, further research is needed to determine the exact mechanism by which vitamin D reduces the risk of death from cancer.
Does vitamin D deficiency affect cardiovascular disease risk?
Research has identified that vitamin D plays a role in cardiovascular health by acting on endothelium and smooth muscle tissue to regulate blood pressure, and further research has identified vitamin D deficiency and symptoms such as type 2. The association with cardiovascular disease in people with pre-existing risk factors is reviewed. diabetes or high blood pressure.
However, a 2021 review claims that “there is no strong evidence for the beneficial effects of vitamin D on CVD.” [cardiovascular disease] “Risks,” he said, pointing to contradictory evidence from observational studies and randomized controlled trials.
Recent studies aimed to assess the association between vitamin D levels and cardiovascular disease and cardiovascular events (such as heart attacks and strokes). Analysis of 5,684 participants from Lausanne, Switzerland. The mean follow-up period in this study was 14.4 years.
Vitamin D status was divided into three categories based on serum 25(OH)D. Normal, dysfunctional (21– 29 ng 25(OH)D/mL) or deficiency (<20 ng/mL). Researchers found that vitamin D deficiency was associated with an increased likelihood of cardiovascular events, but not with cardiovascular disease or overall mortality.
The authors outlined that the number of cardiovascular events during the study period was relatively low, and that analysis of a larger study cohort may clarify the impact of vitamin D on cardiovascular health. suggested.
Vitamin D deficiency and increased sepsis mortality in the elderly
Another recent study published in nutrients, revealed the impact of severe vitamin D deficiency on mortality in older adults with sepsis. Of the 129 patients recruited to this study, 96 had vitamin D deficiency, of which 62 patients had severe deficiency (serum 25(OH)D <12 ng/mL). The researchers classified patients using the Sepsis 3 definition. A continuous organ failure assessment score of 2 or higher is considered sepsis.
Researchers confirmed that severe vitamin D deficiency was associated with increased 14-day mortality, 28-day mortality from sepsis, and overall in-hospital mortality. In their paper, the authors highlight the role of vitamin D in immunity as a potential mechanism for this association, but note that “the pathophysiology by which vitamin D deficiency influences sepsis mortality remains unclear. ” is outlined.
Vitamin D deficiency identified as a risk factor for early-onset dementia
early-onset dementia – If symptoms of dementia appear before age 65 – Previously thought to have a genetic cause; new research was announced on JAMA Neurology tried this.
By assessing more than 350,000 people under the age of 65 in the UK, researchers identified 15 risk factors for early-onset dementia, including vitamin D deficiency.
Although more research is needed, this study shows how vitamin D status and other modifiable risk factors can be incorporated into dementia prevention strategies.
Huffman concludes: – Encourage patients to meet their vitamin D needs. Therefore, it may be necessary to integrate sunlight exposure with dietary intake or supplements, as appropriate. ”
Dr. Kevin Huffman was speaking with Katie Brighton, Scientific Copywriter at Technology Networks.
About the interviewee: Dr. Kevin Huffman is a primary care physician and medical director of Florida Injury Center. He has 35 years of experience as a primary care physician and has extensive knowledge in the diagnosis, treatment, and management of nutritional deficiencies and their comorbidities.
