Vitamin D : Key to your strength
Vitamin D, also called the sunshine vitamin, is a fat-soluble vitamin. It is needed in the body in large quantities, as it is responsible for the health of our bones and teeth, helps in fighting off infections and even improves mental health. Not only is it a vitamin, it is also a hormone and helps regulate insulin and calcium levels in the blood.
The human body makes vitamin D when exposed to sunlight, or more specifically UVB rays. Plants have vitamin D in the form of ergosterol while cholesterol is the corresponding basic building block of vitamin D in humans. When a leaf of a plant is exposed to sunlight, it converts ergosterol into ergocalciferol or vitamin D2. In the same way, when human skin is exposed to sunlight, the body converts cholesterol into cholecalciferol, a form of vitamin D3. In humans, unlike in plants, this conversion is not the final step before vitamin D can be utilised by us. Cholecalciferol is converted into hydroxyl vitamin D in the liver, kidney, skin, brain and prostate. Next this is converted to dihydroxy vitamin D in the lungs, colon, spleen, liver, kidney, stomach and lymph nodes. This is the most active form of vitamin D required by humans and it lasts for a short time before it is eliminated so we constantly need vitamin D, much more than we thought was earlier required.
Sales of Vitamin D have continued to skyrocket for the past decade, as scientific research demonstrates a wide array of Vitamin D benefits that also takes care of our bones . In response to the overwhelming body of research, the Institute of Medicine recently boosted the recommended dietary intakes (RDI) of Vitamin D.
With the release of the new RDIs, sales of the sunshine vitamin are likely to soar even higher in 2011.Nutritionists believe that it will be difficult to meet the new RDIs for Vitamin D through diet alone, particularly if you eat only limited dairy products or do not regularly include fish in your diet. A dietitian in Boston, says "There's no way that people will satisfy those recommendations for vitamin D without supplements." Not many foods contain Vitamin D which is why most people will need to modify their diets to include Vitamin-D fortified foods and beverages along with an increased intake of milk, eggs and fish. Consuming 600 IUs a day of Vitamin D from a single food would require drinking 6 cups of milk or eating 15 servings of Vitamin-D fortified cereals.3
Some experts even believe the new RDIs for Vitamin D are still too low. In response, Dr for the Council for Responsible Nutrition said, "While an increase in the recommendations for vitamin D will benefit the public overall, such a conservative increase for the nutrient lags behind the mountain of research demonstrating a need for vitamin D intake at levels possibly as high as 2,000 IU/day for adults." Doctors who concur with this view may consider prescribing a higher daily dose of Vitamin D to their patients as the upper safety limit has been set at 4,000 IUs for those aged 9 and above.
Exposing yourself to sunlight is the most important source of vitamin D because sunlight is far more likely to provide you with your vitamin D requirement than food is. Mushrooms that have been irradiated and yeast are vegetarian sources of this valuable vitamin. Other non vegetarian sources of vitamin d are Fish like salmon, mackerel, catfish, sardines and tuna, eggs, Fortified milk, cheese, butter, Oysters, Fortified breakfast cereals, soymilk and margarine.