What Does Vitamin D do for your health? What are symptoms and signs of vitamin D deficiency?

By the turn of the 20th century, 90% of the children living in New York, Boston, and Leyden in the Netherlands were afflicted with rickets, a bone-deforming disease. The first observation of this disease was in the mid-1600s by Whistler and Glissen, who reported that children living in industrialized cities in

Great Britain had short stature and deformities of the skeleton, especially of the lower legs. It wasn't until 1889 that the discovery that "sunbathing" was important for preventing rickets came about.

Since then, many other health benefits of vitamin D have been discovered. These include the following:

Skeletal disease: Anyone taking calcium knows that you need to take it with vitamin D. It's needed because vitamin D promotes calcium absorption in the gut and maintains blood calcium levels to enable normal mineralization of bone and prevent abnormally low blood calcium levels that can then lead to tetany. Adequate vitamin D levels can prevent bones from becoming thin, brittle, or malformed. It is linked with the prevention of osteomalacia, osteopenia, and osteoporosis.

Fall prevention is a public-health goal for the elderly. Each year, one in three people 65 years and older experiences at least one fall, with 5.6% resulting in a fracture, and vitamin D can play a role in preventing this. There are vitamin D receptors in human muscle that have a direct effect on muscle strength. A severe vitamin D deficiency can cause myopathy, which can cause muscle weakness and pain. Vitamin D supplementation can reverse this and improve balance. Supplementing 700 to 1,000 IU/day of vitamin D3 has been shown to reduce falls by 19%-26%.

Another advantage to correcting a vitamin D deficiency has been seen in decreasing knee and hip pain. A longitudinal population-based cohort study of 769 randomly selected older adults aged 50-80 years found that moderate vitamin D deficiency predicts the incidence or worsening ofknee pain over five years and possibly hip pain over 2.4 years.

Cancer: The link between the sun and cancer is typically not seen as a positive one because of the connection with skin cancer. UV-B radiation from the sun is said to be the most important environmental risk factor for nonmelanoma skin cancer. Because the sun is the primary source of vitamin D, researchers are looking to see what role it plays in skin cancer. Some believe that enough sun exposure to keep your vitamin D levels up while protecting your skin from damage is beneficial to skin cancer survival. There has also been research to show the protective effect that vitamin D has with the development of other cancers, including colon, breast, and prostate cancer.

In 1941, U.S. pathologist Frank Apperly published geographic data that demonstrated for the first time an inverse correlation between levels of UV radiation in North America and mortality rates from cancers. This means that more exposure to UV radiation (sun) leads to fewer deaths from cancers. Since this was published, it has been confirmed that there is an association between an increased risk of dying of various internal malignancies (for example, colon, breast, ovarian, melanoma, and prostate cancer) and living far from the equator

Cardiovascular disease: Vitamin D deficiency is associated with an increased prevalence ofhypertension, hyperlipidemia, peripheral vascular disease, coronary artery disease, myocardial infarction, heart failure, and stroke. The anti-inflammatory effects of vitamin D may be the reason for this. Research is being done to determine exactly how this works and why.

Infections: Do you tend to get more respiratory infections in the winter? Vitamin D deficiency could be the cause. Observational studies have shown an association between low vitamin D status and an increased risk of both upper and lower respiratory tract infections. The role of vitamin D in reducing the risk of hospital-acquired infections, such as pneumonia, bacteremias, urinary tract infections, and surgical site infections is also being investigated.

Depression: The association between lack of sunlight and depressive disorders was first noted 2,000 years ago. Vitamin D plays a role in regulating adrenaline, noradrenaline, and dopamine production in the brain through vitamin D receptors in the adrenal cortex, as well as protecting against the depletion of serotonin and dopamine. This is the possible link with vitamin D's role in depression. The research is new in this area, and only the associations have been shown so far. Vitamin D deficiency has been associated with an 8%-14% increase in depression. Research is also finding a relationship with low vitamin D levels and increased risk ofsuicide. In a study done on the Department of Defense Serum Repository personnel, researchers compared the vitamin D levels of 495 verified suicide cases versus 495 controls. They found the lowest 25(OH)D level are associated with an increased risk for suicide. Another study compared vitamin D levels in 59 suicide attempters, 17 nonsuicide depressed patients, and 14 healthy controls. The suicide attempters had significantly lower vitamin D than depressed nonsuicidal patients and healthy controls. Research is ongoing in this area to determine if you can prevent and treat depression by correcting vitamin D deficiencies

Multiple sclerosis: Evidence continues to accumulate supporting the role of vitamin D and the prevention and treatment of multiple sclerosis (MS). It begins with the vitamin D levels in pregnant women. Numerous studies have linked the occurrence of MS with birth month. There is a high prevalence of MS in high-latitude areas. The lack of sunlight exposure appears to be a significant predictor, and research is ongoing in this area.

Tuberculosis: Individuals with tuberculosis (TB) have been shown to have lower vitamin D levels than healthy people. Supplementation has shown to improve symptoms in these individuals. Further studies are needed to determine the cause and appropriate intervention.

Reducing the risk of type 2 diabetes: Research has shown that those with blood vitamin D levels over 25 ng/mL had a 43% reduced risk of developing type 2 diabetes compared with those with levels under 14 ng/mL.

Decreasing inflammation: Many of the health benefits associated with vitamin D may come from its role in decreasing inflammation. Research has shown a decrease in levels of C-reactive protein, a marker of inflammation, with increased levels of vitamin D to just below 21 ng/mL.

Reducing risk of allergies in children and adolescents: A nationwide study of over 6,000 individuals showed that allergic sensitization was more common in those with vitamin D levels under 15 ng/mL versus those with levels 30 ng/mL or more.

Sleep apnea: There is some evidence that vitamin D deficiency may increase the risk of obstructive sleep apnea brought on by inflammatory rhinitis and/or tonsillar hypertrophy. More research needs to be done to confirm this.

Decreasing dental cavities: A review of 24 controlled clinical trialsencompassing 2,827 children found a 47% reduced risk of cavities with vitamin D supplementation.

Possibly helping with erectile dysfunction (ED): It is not clear if increasing your serum vitamin D levels can help with ED. Many men diagnosed with ED are diagnosed with cardiovascular disease (CVD) within a few years. Vitamin D deficiency is linked with CVD, so if you are deficient in vitamin D, some researchers believe that treating this could reduce your risk of ED.