Vitamin D Kalciferol

A rare vitamin obtained by sunlight on the skin,
also known as kalciferol

While most of vitamins are obtained from foods we eat, the vitamin D is the only vitamin that's not available from foods. Instead, vitamin D is actually obtained by sunlight on the skin. These days there's a lot of media coverage about the dangers of getting too much sun. While those warnings are warranted up to a point, what's being overlooked is that it is essential that the skin is exposed to sunlight to obtain the recommended daily allowance of the D vitamin. In reality, the amount of time that a person has to spend in the sun to receive a sufficient dose of the D vitamin is extremely small and just a few minutes a day will be sufficient and not have any adverse effects from the amount of ultra-violet light received.

The oldest prohormone on Earth

Some don't even consider vitamin D to be a vitamin, but rather the oldest prohormone on Earth, essential to wellbeing of all living creatures, from phytoplanktons to human beings. Prohormones are the substances the body converts into hormones. In this instance, vitamin D is produced by kidneys to control calcium levels in the blood, which also has an effect on the immune system. The body produces several varieties of these hormonal substances, of which the most important is calcidiol. Overall, about ten percent of vitamin D is absorbed from food, while the rest the body makes up, in which process sunlight exposure is critical.

While you can obtain some vitamin D from supplements, the majority of your vitamin D is obtained directly by sunlight - your body's exposure to sunlight stimulates your body to produce some 90% of your vitamin D needs.

COVID-19 and Vitamin D

A recent study in Spain has also highlighted the importance of vitamin D in the current COVID-19 pandemic. It was found that up to 80% of people with coronovirus were found lacking in vitamin D. Don't get wrong idea that vitamin D will save you from conoronavirus. Instead, this emphasizes the importance of strong immunity, as one of the benefits of this vitamin is boosting our immunity.

Vitamin D Controls Calcium Absorption

The most important function of the D vitamin is to help control how much calcium is absorbed from food. The majority of the calcium is used to build strong teeth and bones but it is also needed to send messages along the nerves and to help muscles, such as the heart muscles, to contract. It is the D vitamin that ensures that there is always sufficient calcium in the blood to perform these tasks. Other functions that require the D vitamin relate to the immune system and it is believed that it is also a contributing factor in reducing the risk of contracting cancer and, in particular, colon cancer.

Vitamin D3

The variant of the D vitamin that is formed under the skin is known as vitamin D3, or cholecalciferol. This D vitamin is created when the ultraviolet in the sunlight reacts with a type of cholesterol that is found under the skin naturally. The D3 is converted into a more active form of the d vitamin in the liver and is then diverted to where it is needed the most. Some of the D vitamin remains in the liver and kidneys to help reabsorb the calcium from the blood. The rest of the D vitamin is dispersed to the bones to help them retain their calcium and the intestines to aid absorption of calcium from food.

Technically considered to be a prohormone, vitamin D is mostly produced by the body exposed to direct sunlight, while small amount is gained via food and supplements.

Vitamin D2

Even though the majority of the D vitamin is formed through the exposure of the skin to sunlight there are some foods that do contain some of the vitamin naturally. This form of the D vitamin is known as vitamin D2, or ergocalciferol. This is used in the same way as the other D vitamins and is the type used to create the majority of D vitamin supplements. This type of vitamin usually comes from plant sources.

There are also two more recognized forms of the D vitamin: vitamin D4 and vitamin D5.

Vitamin D Deficiency

Vitamin D deficiency can cause muscle weakness and bone fragility. There are two bone softening diseases caused by vitamin D deficiency (in amongst other things):

1. Rickets - usually a childhood disease that impedes growth and causes deformity of the long bones.
2. Osteomalacia - an adult disease that causes muscle weakness and bone fragility.

Vitamin D Benefits

While it's mostly known by its ability to assist healthy bones, vitamin D offers other health benefits:

• helps immune system
• reduces incidence of influenza
• has potential to prevent cancer
• reduces the risk of high blood pressure and artery disease
• slows aging and reduces overall mortality
• reduces inflammation

Eggs, bread, milk products, meat and seafood are good sources of vitamin D. But remember you still have to go on sunlight, for the body to convert these food ingredients into active form of vitamin D, useful for the bones and immunity.

Vitamin D Sources

As noted earlier in this article, the body produces about 90 percent of vitamin D needs itself using photochemical process (when exposed to direct sunlight), while the other 10 percent comes from food. Nonetheless, obtaining enough of this vitamin from food as prohormone, helps the body to convert it into hormonal substances, known as vitamin D.

Some of the best vitamin D sources include:

• Seafood - salmon, catfish, eel, mackerel and tuna
• Dairy products - milk and yoghurt
• Breakfast cereals - fortified with vitamin D
• Meats - lean meats and beef liver
• Oils - cod liver oil, oil spreads, margarine
• Eggs - egg yolks
• Mushrooms

Anticancer Benefits

Some of the more recent studies have shown that vitamin D can play an important role in defending the body against cancer, or at least slowing down its progress.

Read more about this in our recent new update on vitamin D anticancer benefits.

Catch on some sunlight today and load up on your vitamin D!

Guide to Vitamins
Vitamins Food Sources	Multivitamins Benefits	Vitamin A Beta Carotene	B Vitamins Group
Vitamin B1 Thiamin	Vitamin B2 Riboflavin	Vitamin B3 Niacin	Vitamin C Ascorbic Acid
Vitamin D Kalciferol	Vitamin E Tocopherol