Vitamin D and Adult Health

Abstract

· Many adults are  vitamin  D deficient.

· People most likely to suffering of lack of  vitamin  D are the elder, people who need to avoid sunlight due to skin conditions, dark-skin people, and people unable to absorb the  vitamin  D for various reasons.

· It is recommended daily exposure of at least parts of the body to sunlight for the synthesis of  vitamin  D. It is recommended sunbath between 10 AM and 2 PM in summer should be avoided.

· It is recommended 400 IU of  vitamin  D supplementation a day.

 Vitamin  D

 Vitamin  D is composed of two molecules; Cholecalciferol, known as  Vitamin  D3, and Ergocalciferol which is also referred to as  Vitamin  D2. Cholecalciferol is synthesized by UV light in the skin. Ergocalciferol is the form of  Vitamin  D extracted from plants which have been exposed to and absorb UV light.

 Vitamin  D is an important part of a healthy diet to promote proper bone function and strength. Working in part with calcium,  Vitamin  D provides bones with the nutrients needed to maintain strong and healthy bones, preventing fractures, breaks and bone loss.

Once ingested  Vitamin  D is metabolized by the liver, and then hydroxylated in the kidneys to produce the most active form, to facilitate the absorption of phosphate and calcium, mineralization of the skeleton and extracellular homeostasis with the help of parathyroid hormones.

Recommended Dosage of  Vitamin  D

The majority of  Vitamin  D retained by adults is from sunlight; however it is important to note that  Vitamin  D consumption should not be based only on sunlight. Adults should consume about 400 IU daily. Sunlight exposure for an average of 15 minutes yields absorption of 1/3 of the minimal erythemal dose. While sunblock is important for prolonged sun exposure to prevent damage to skin, direct short exposure of the hands, arms and face to the sun while it is not intense is recommended for about 15 minutes. Sunblock prevents the penetration of UVA and UVB rays from the sun; UV rays are the necessary component for  Vitamin  D synthesis. During hotter months, it is advised to avoid direct sun exposure without sun block between 10AM and 2AM to prevent risks of serious skin damage.  Vitamin  D is also found in several foods. Listed from highest to lowest IU value, they are: salmon, mackerel, tuna fish, fortified milk, fortified margarine, egg yolk and beef liver. Pure cod liver oil supplements are also a good source of  Vitamin  D, yielding a high IU value for a small amount. Since most adults consume less than 100 IU daily from diet, supplemental forms of  Vitamin  D are recommended, especially for those who do not receive proper sun exposure. The recommended intake by the FDA is:

 Vitamin  D intake

Daily intake

Age IU mcg

0 – 50 200 5

51 – 70 400 10

71 + 600 15

Groups at risk

Certain adults are more at risk than others. Generally the elderly are most susceptible to more serious  Vitamin  D deficiencies. This group usually does not receive as much sun exposure or consume as many foods with  Vitamin  D. Supplements are very highly recommended for the elderly. Hospital patients, especially those with hip fractures are also more susceptible to deficiencies of  Vitamin  D. Women who have a very dark skin tone are also at a very high risk; if the woman is usually veiled, this factor increases the risk further.

 Vitamin  D deficiency

 Vitamin  D deficiencies are classified in three different forms: mild, moderate and severe. Each deficiency is rated on a scale level of 25-OHD.

Mild  vitamin  D deficiency ranges between 25-50 nmol/L and result in the increase of secretions of parathyroid hormones and higher bone turnover.

Moderate  vitamin  deficiency ranges between 12.5-25 nmol/L and results in higher bone turnover and reduced density; usually a higher risk of hip fracture is associated with moderate deficiency as well.

Severe  vitamin  D deficiency rank below 12.5 nmol/L; results of severe deficiency are osteomalacia. Persons with osteomalacia experience pain in muscles and bones, along with frequent and severe fractures.

Toxicity

Toxicity is caused by excess ingestion of  vitamin  D supplementation not by exposure to the sunlight. There are no evidences of toxicity by doses lower than 4 000 IU daily.

 Vitamin  D and Prostate Cancer

Prostate cancer is one of the major cause of deaths. Every year about 220,000 men are diagnosed with prostate cancer in the USA. Doctors may sustain that  vitamin  D is not beneficial for cancer of the prostate until further studies proves its help. Following that approach two things can happen: The patient may die while the conclusions of such studies are still pending or it can miss the point. Men diagnosed with cancer in the prostate cannot afford to be  vitamin  D deficient and neither should do their doctors although  vitamin  D should not be considered as the only treatment of prostate cancer. Evidences suggest that the proper intake of  vitamin  D3 may help fighting prostate cancer.  Vitamin  D Acknowledgments

A paper from Feldman and the Stanford University states: “Based on these findings, we postulate that  vitamin  D may have protective actions on the development and/or progression of prostate cancer…We further hypothesize that  vitamin  D supplementation may have beneficial effects on retarding the development and/or progression of prostate cancer.” This is the first evidence of the usefulness of the Cholecalciferol in the prevention and treating of prostate cancer. Cholecalciferol, Calcidiol and Calcitriol

Several scientific studies have been conducted since 1998 by American universities on  vitamin  D and its role in the prevention and treatment of prostate cancer. It was found that the  vitamin  D raises the level of plasma calcidiol. The Calcitriol is made by the kidneys from the calcidiol which has been considered as beneficial for the treatment of prostate cancer. The easiest way to raise calcidiol levels is through supplementation of Cholecalciferol. Further studies show that calcidiol is just as effective as calcitriol in inhibiting prostate cancer growth.

Calcitriol Breakdown Reduced by Soy Isoflavonoids

In 2003, two studies from at the University of Vienna Medical School confirmed that the isoflavonoids in soy dramatically reduce the breakdown of calcitriol in prostate cancer cells. In fact, they found that such products profoundly inhibit the enzyme that metabolizes calcitriol, reducing its activity to almost zero. This again raised the possibility that such compounds could be combined with  vitamin  D to treat prostate cancer. A study from the University of Toronto presented by Woo, Vieth, in 2004 showed that 2,000 IU of simple  vitamin  D3 (Cholecalciferol) either reduced or prevented further increases in PSA in the majority of men with advancing prostate cancer.

 Vitamin  D supplementation

There are a few supplements of concentrated form of  Vitamin  D available used to treat  Vitamin  D deficiencies. Most supplements contain the highest level of 1,000 IU. Depending on the severity of deficiency, it may be required supplementation between 3,000 and 5,000 IU daily for adequate replacement therapy. Other supplements containing  Vitamin  D address specific issues but depending on the formulation they can also be used for general use or other. Some formulations for helping prostate health contain 1,600 IU of  Vitamin  D3 in one single dose. Prostate-C is considered one of the best products available and can be found online.

Source by Fred MacePhoto by Apotek Hjartat

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