Our body being made of 100 trillion cells needs 90 nutrients daily. Out of which Vitamin D is most important. Known as the sunshine vitamin, Vitamin D is produced when your skin is exposed to sun rays, or rather, the ultraviolet B (UV-B) radiation of the sun. Vitamin D functions more like a hormone, and every single cell in your body has a receptor for it. The major biological function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Also it triggers the body’s immune cells to produce antibodies; therefore, vitamin D promotes an overall increase in the strength of the immune system

Known as the sunshine vitamin, vitamin D is produced by the body in response to skin being exposed to sunlight. It is also occurs naturally in a few foods -- including some fish, fish liver oils, and egg yolks -- and in fortified dairy and grain products.

Vitamin D is essential for strong bones, because it helps the body use calcium from the diet. The recommended daily intake (RDI) is usually around 400–800 IU, but many experts say you should get even more than that.

Studies report that it triggers the body’s immune cells to produce antibodies; therefore, vitamin D promotes an overall increase in the strength of the immune system

Vitamin D is produced when your skin is exposed to sunshine, or rather, the ultraviolet B (UV-B) radiation that the sun emits. The amount of vitamin D that your skin makes depends on such factors as:

  1. The season: This factor depends a bit on where you live. In areas such as Cleveland, OH, the UV-B light does not reach the earth for six months out of the year due to the ozone layer and the zenith of the sun.

  2. The time of day: The sun's rays are most powerful between 10 a.m. and 3 p.m.

  3. The amount of cloud cover and air pollution.

  4. Where you live: Cities near the equator have higher ultraviolet (UV) light levels. It is the UV-B light in sunlight that causes your skin to make vitamin D.

  5. The melanin content of your skin: Melanin is a brown-black pigment in the eyes, hair and skin. Melanin causes skin to tan. The darker your skin, the more sun exposure is needed in order to get sufficient vitamin D from the sun.

Symptoms Of Vitamin D Deficiency:

  • Vitamin D's most important roles is keeping your immune system strong. It is responsible for fighting infection. If you often become sick, especially with colds or the flu, low vitamin D levels may be a contributing factor. Vitamin D supplements at a dosage of up to 4,000 IU daily may reduce your risk of respiratory tract infections

  • Excessive sweating or change in sweating patter can be cause of deficiency

  • Feeling tired can have many causes, and vitamin D deficiency may be one of them. A woman who complained of chronic daytime fatigue and headaches was found to have a vitamin D blood level

  • It improves your body's absorption of calcium. Bone pain and lower back pain may be signs of inadequate vitamin D levels in the blood.

  • In studies, researchers have linked vitamin D deficiency to depression, particularly in older adults. And Slow healing of wounds after surgery or injury may be a sign that your vitamin D levels are too low.

  • Vitamin D plays a crucial role in calcium absorption and bone metabolism. Many older people who are diagnosed with bone loss believe they need to take more calcium. However, they may be deficient in vitamin D as well. Low bone mineral density is an indication that your bones have lost calcium and other minerals. This places older adults, especially women, at an increased risk of fractures.

  • Hair loss is often attributed to stress, which is certainly a common cause. However, when hair loss is severe, it may be the result of a disease or nutrient deficiency. Hair loss in women has been linked to low vitamin D levels.

  • When you don’t have enough vitamin D, you feel hungry all the time, no matter how much you eat. That is because low levels of vitamin D interfere with the effectiveness of leptin, the appetite hormone that tells you when you are full. When vitamin D is replenished and back to normal levels, leptin’s actions are restored, thus creating feelings of satiety and aiding in weight loss.

The Bottom Line is:

Vitamin D deficiency is incredibly common and most people are unaware of it. That's because the symptoms are often subtle and non-specific, meaning that it's hard to know if they're caused by low vitamin D levels or something else. If you think you may have a deficiency, it's important that you speak to your doctor and get your blood levels measured. Fortunately, a vitamin D deficiency is usually easy to fix. You can either increase your sun exposure, eat more vitamin-D-rich foods

Lets Discuss what are the food which are rich in vitamin D:

  • Salmon

  • Cod liver oil

  • Herring and sardines

  • Tuna

  • Egg yolks

  • Mushrooms

  • Fortified foods

  • Soy milk

  • Orange juice

  • Cereal and oatmeal