Vitamin D is entirely different from the other vitamins.
In fact, it’s a steroid hormone produced from cholesterol when your skin is exposed to the sun.
Vitamin D is sometimes referred to as "the vitamin of sunshine" for this reason.
Sun exposure, however, seldom offers enough vitamin D, making it necessary for supplements or your diet to receive it.
However, only a handful of foods contain large amounts of this essential vitamin, and deficiency is very common.
What is Vitamin D?
Vitamin D is important to the functioning of many musculoskeletal, gastrointestinal, endocrine, immune, and cardiovascular systems throughout the body. That's why preserving sufficient levels of vitamin D is so critical for human health as a whole.
Perhaps one of vitamin D's most interesting facts is that it's not really a vitamin. In fact, it is a fat-soluble hormone released in the body when the skin is exposed to sunlight. We can get some, albeit rather limited, dietary vitamin D. In nature, very few foods contain vitamin D. Vitamin D is present in some fatty fish, such as wild caught salmon, fish liver oils, egg yolk, mushrooms, butter, liver and fortified foods such as milk (but not in farm raised salmon). But having enough vitamin D from a diet alone is really very difficult.
Two main dietary forms exist:
Vitamin D3 (cholecalciferol). Found in some animal foods, like fatty fish and egg yolks.
Vitamin D2 (ergocalciferol). Found in some plants, mushrooms, and yeasts.
Of the two, D3 (cholecalciferol) seems to be almost twice as effective at increasing blood levels of vitamin D as D2 (ergocalciferol).
What Does Vitamin D Do in Your Body?
In order for vitamin D to become activated in the body, it has to undergo two hydroxylations. First, it is converted to 25-hydroxyvitamin D [25(OH)D] in the liver. And then the physiologically active 1,25-dihydroxyvitamin D, also known as calcitriol, is formed primarily in the kidneys. The circulating form of vitamin D is 25(OH)D and that’s what is measured to determine vitamin D status.
Vitamin D affects different cells that are connected to bone health. It facilitates the absorption of calcium and phosphorus from your gut, for instance.
But scientists have recently found that in other areas of health, such as immune function and cancer defense, it also plays a role.
Effective Way to Get Vitamin D Is Sunshine
When it is exposed to ultraviolet B (UVB) rays from the sun, vitamin D can be produced from cholesterol in your skin.
You will probably get all the vitamin D you need by sunbathing a few days a week if you live in a place with ample sunshine.
Bear in mind that a major part of the body needs to be revealed. You can contain far less vitamin D if you're only showing your face and hands.
Also, you can generate less vitamin D or none at all if you remain behind glass or use sunscreen.
However, when remaining in the sun for long periods, you should make sure to use sunscreen. Sunshine is safe, but sunburn can lead to premature aging of the skin and increase your risk of developing skin cancer.
To Sum It Up
Vitamin D is a vitamin essential for bone health that is fat-soluble.
Growing intake can also decrease depression and enhance strength for those low in this nutrient.
When exposed to sunlight, the skin contains vitamin D. As well as some fortified foods and vitamins, foods such as fatty fish, fish oil, and liver also contain vitamin D.
Because of insufficient sunlight exposure and a restricted range of rich dietary sources, deficiency is fairly normal. Consider supplementing if you do not spend much time in the sun and rarely eat fatty fish. To improve your health, having enough vitamin D will go a long way.