Vitamin D offers numerous health advantages, from bone and muscle support to relieving inflammation and fatigue. As a fat-soluble vitamin, it plays a key role in cell division as well as calcium absorption. Furthermore, its antimicrobial effects boost immune systems while supporting brain health.

Nursing pioneer Florence Nightingale discovered that sick patients placed in rooms filled with sunlight recovered more rapidly than those located in dim rooms. Since then, experts have recognized sunlight’s healing power in increasing recovery times for sick individuals.

Reduces the Risk of Cancer

Studies demonstrating the efficacy of vitamin D as an anticancer agent are numerous, both epidemiologically and clinically. Vitamin D receptor (VDR), a nuclear protein that binds with 1,25-dihydroxyvitamin D (1,25(OH)2D) hormone-like substance to regulate proteins responsible for cell growth and differentiation as well as proliferation/apoptosis processes in cells. Numerous experimental trials have confirmed this hypothesis that 1,25(OH)2D inhibits tumor formation across several cancer types including breast, lung lung/colon prostate and bone cancers while increasing survival preclinically models in preclinical models.

The US Public Health Service Task Force recommends an intake of 600 International Units (15 micrograms) of Vitamin D daily for adults 19 years or older with minimal sun exposure, according to their recommendations for adults 19 years old or over. Other countries and professional societies may have slightly differing recommendations due to varying biological, clinical implications of vitamin D as well as various methods used in observational studies and randomized clinical trials to establish guidelines.

VITAL was a randomized clinical trial which followed 25,871 men and women 50 years of age or older who were cancer free when starting and had adequate serum 25(OH)D levels at baseline. Over an average 5.3 year period, supplementation with 2,000 IU per day of vitamin D3 plus 1,000 mg per day of marine omega-3 fatty acids helped decrease colorectal cancer incidence but not other forms.

People with dark skin do not produce enough Vitamin D from sunlight alone, necessitating higher doses of both dietary and supplemented vitamin D in order to reach normal blood levels. Obesity further limits synthesis as fat cells store it along with the enzymes necessary for its release; liver and kidney diseases also limit vitamin D production, decreasing the amount of enzymes responsible for turning vitamin D into its active form.

Prevents Osteoporosis

Vitamin D is vital in supporting bone health. It promotes intestinal absorption of calcium and phosphate and increases parathyroid hormone activity, while low levels can result in impaired calcium absorption leading to negative calcium balance and bone resorption. According to one multi-national survey, 31% of postmenopausal women diagnosed with osteoporosis had 25-hydroxyvitamin D concentrations below 30 ng/mL.

Vitamin D deficiency is often caused by spending too much time indoors without enough sun exposure, eating an unbalanced diet or having medical conditions which impede its absorption.

Vitamin D can be obtained through sunlight exposure, diet or prescription supplements; to avoid deficiency it is essential that these sources be balanced out appropriately; generally speaking 50nmol/L (20ng/ml) should suffice.

People with dark skin produce less Vitamin D from sunshine and may require year-round supplementation with either Vitamin D3 (cholecalciferol) or its plant counterpart, Vitamin D2 (ergocalciferol). A few natural sources of Vitamin D exist such as oily fish such as salmon and sardines, eggs and liver – as well as fortified margarine and dairy products containing this essential nutrient.

Most doctors recommend healthy adults receive 400 to 1000 IU of vitamin D every day from food and supplements, although this amount may need to be higher for those at risk for osteoporosis or other conditions affecting absorption of Vitamin D. Before taking too much vitamin D it’s essential to discuss its dosage with your physician as too much Vitamin D can lead to nausea, vomiting, muscle weakness and confusion as well as build-ups of calcium in kidneys and bloodstream which affect heart function negatively.

Reduces the Symptoms of Asthma

Asthma is a chronic lung condition that makes breathing difficult, sometimes life-threatening in severe cases. Researchers have discovered that higher levels of Vitamin D can reduce its symptoms such as wheezing and shortness of breath by modulating immune system functions and reducing inflammation; furthermore it acts as a calcium metabolite to allow bodies to absorb and use calcium more easily, strengthening bones.

Studies have demonstrated a correlation between low vitamin D levels and asthma and poor asthma control, and low levels of Vitamin D consumption. Researchers believe this vitamin could help prevent asthma attacks by helping ward off colds or upper respiratory infections that trigger it in some people and decreasing airway inflammation that results in wheezing and reduced air entry characteristic of asthma attacks.

Cochrane review of nine double-blind placebo-controlled trials that involved over 1,093 participants did not find evidence that vitamin D supplementation improved asthma outcomes in people who already took conventional forms (cholecalciferol) of Vitamin D supplements; however, further investigation may show some benefit of the hydroxylated metabolites like calcidiol to people living with asthma; more research needs to be conducted in this regard.

Vitamin D can be found in most multivitamins or as an individual supplement. Before adding Vitamin D to your treatment plan, however, consult with your healthcare provider as certain medications interact with Vitamin D. Furthermore, too much Vitamin D may cause calcium absorption problems as well as damage kidneys and hearts if too much is taken at once; general consideration suggests daily dosage of less than 100 micrograms is safe.

Reduces the Symptoms of Allergies

Vitamin D3, or cholecalciferol or D3, is produced when skin is exposed to sunlight, leading many people to refer to it as the “sunshine vitamin.” Unfortunately, not everyone receives enough of this essential nutrient, especially during winter months when sun exposure may be limited. Although diet plays a part in providing this essential nutrient, most foods don’t naturally contain enough of this vital nutrient to meet daily requirements for adequate vitamin D levels.

Making time each day to step outside for at least a few minutes and expose your skin to sunlight is the ideal way to increase vitamin D intake; however, those living in areas with limited sun or covering themselves to minimize risk should consider taking vitamin D supplements throughout the year.

If you find yourself exhausted, experiencing bone pain or muscular weakness, and have low vitamin D levels it could be an indicator that you require medical assistance for testing to monitor these levels and recommend an increase in dosage or prescribe supplements if deficiency exists. If so, your healthcare professional may prescribe or suggest higher dosage solutions as appropriate.

Reduces the Symptoms of Depression

Studies have linked low levels of vitamin D with increased depression risk; however, few trials have proven its efficacy at relieving or preventing symptoms. This may be due to difficulties conducting placebo-controlled trials on people suffering from depression who tend to avoid outdoor activities and have lower-than-usual intakes of Vitamin D due to poor appetite or avoidance behavior – leading them to take in less Vitamin D overall than usual and therefore making conducting studies harder and providing accurate reports on severity of depression more challenging.

However, two recent meta-analyses of trials regarding supplemented Vitamin D and depression have demonstrated some antidepressant benefits of supplementing. Gowda et al focused on trials which measured subsyndromal depressive symptoms; Vellekkatt and Menon studied clinical depression or syndromal depression respectively.

Both meta-analyses utilized standardized methods of data collection from participants and comparison of results, using only RCTs that were double-blind to reduce bias and false associations, while also accounting for key confounding factors such as age, gender, baseline Vitamin D levels, presence or absence of other medical conditions, or measures of depression.

Analysis revealed that those with baseline vitamin D levels at or below 50 nanomoles per liter – considered deficiency threshold levels – experienced significant benefits, as most RCTs don’t assess these levels, and those that did tend to use cross-sectional or cohort studies rather than RCTs which are better at establishing causality. This result was particularly notable given that most RCTs don’t monitor vitamin D levels within samples used; those that did so tended towards cross-sectional or cohort research rather than RCTs which preferentially establish causality.