What Is Vitamin D And Why Is It So Important?

For 2 years I was unwittingly working in a cupboard.

My office window to the atrium was boarded over for a major refurbishment.

By chance I had a blood test for another complaint and instead of having a normal level of 40 to 80 ng/ml, it was 12.

No wonder I felt tired and when I asked around practically my entire team were taking vitamin D supplements!

So if you do not get much natural light, and in winter go to work and go home in the dark, then please read on.

What is vitamin D?

Vitamin D is an important nutrient that is essential for maintaining good health.

It is needed by the body to absorb calcium, which is required for bone health.

Vitamin D is also useful for bolstering the immune system, fighting infections, and maintaining the health of your organs.

But how do you get vitamin D?

Why is happens if your body doesn’t have enough vitamin D?

This guide will share the answers to these questions and many more.

Vitamin D is a group of fat soluble secosteroids (a subclass of steroids).

For humans, the most important compounds in this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol).

Vitamin D differs to most other vitamins because it can be created by the human body.

When your skin is exposed to sunlight, it absorbs UVB radiation which triggers a chemical reaction that turns cholesterol into cholecalciferol (vitamin D3).

You can also obtain vitamin D from food and any vitamin D supplements you consume.

Because vitamin D can be synthesised by the human body it is not technically a vitamin — it is actually a hormone.

When vitamin D first enters the body (via the skin or the food you eat), it is biologically inactive.

It must be converted by the liver and kidneys to become active.

The liver turns cholecalciferol (vitamin D3) into calcifediol and ergocalciferol (vitamin D2) into 25-hydroxyergocalciferol.

These two active forms of vitamin D are what is measured by a doctor when they check your vitamin D levels.

The kidneys also turn calcifediol into calcitriol, another biologically active form of vitamin D.

Calcitriol is a hormone that will flow through in the blood, regulating the body’s intake of calcium and phosphate, which are necessary for healthy bone growth.

Calcitriol also affects cellular growth, immune system function, inflammation, and neuromuscular system function.

What does vitamin D do?

Vitamin D affects the body in many different ways, including:

Strengthening bones and teeth

As mentioned previously, the body needs Vitamin D to process calcium that is present in the foods you eat.

Calcium is an important mineral as it helps your bones and teeth remain strong.

It can also prevent certain diseases that affect the bones like osteoporosis.

Supports the immune system

Researchers have discovered that Vitamin D promotes the development of regulatory T cells, which make the immune system more efficient.

This is particularly useful for people who are suffering from an autoimmune condition as it helps the immune system understand which cells should not be attacked.

Vitamin D also boosts your body’s protective immunity, reducing the chances of bacterial or viral infections.

Helps the brain and nervous system

There are receptors for vitamin D throughout the brain and nervous system.

Researchers have discovered that these receptors allow vitamin D to activate and deactivate enzymes which facilitate nerve growth, protects nerves and reduce inflammation.

Regulates insulin levels

A number of studies have shown that vitamin D can help the body regulate insulin levels.

This makes vitamin D very useful for avoiding conditions like Type II Diabetes or for reducing Type II Diabetes symptoms.

Supports lung function

Scientists have found that vitamin D may help people with serious lung disorders including asthma, COPD, and lung cancer.

Vitamin D helps by reducing inflammation and changing how the structural cells of the lung function.

Researchers are still trying to determine exactly why vitamin D helps the lungs in this way.

Lowers blood pressure

Researchers have found that people with higher levels of vitamin D will have a lower risk of hypertension (high blood pressure).

This occurs because vitamin D binds the receptors that line the blood vessels, reducing cellular buildup that contributes to high blood pressure.

Reduces risk of certain cancers

Recent studies have found that people with high vitamin D levels have a lower risk of contracting a certain types of cancer.

So far, they have found that high vitamin D levels reduce the risk of breast, colon, prostate, ovarian, oesophageal and lymphatic cancer.

Researchers believe that vitamin D reduces the risk of cancer by influencing the expression of certain genes involved in cancer development.

What happens if you are deficient in vitamin D?

Vitamin D deficiency affects an estimated 1 billion people globally.

It increase your risk of some very serious illnesses and can worsen your general health.

Symptoms of vitamin D deficiency include:

• You often get sick
• Bone pain and a sore back
• Bone loss
• Hair loss
• Muscle pain
• Depression
• Wounds take a long time to heal

Fortunately, it is simple to get more vitamin D. You have three options:

Increase how much time you spend in the sun

Spending time in the sun will encourage your body to increase its vitamin D production.

The amount of time you will need to be exposed to sunlight will vary based on the time of year, your geographic location and the colour of your skin (dark skinned people need more time in the sun because the pigment in their skin reduces UV penetration).

In spring/summer, you will probably obtain enough exposure by spending 10 to 15 minutes in the sun three-to-four times a week.

Ideally, you should get your summer sun exposure before 10 am and after 3pm — so you aren’t over-exposed to powerful UV rays during the middle of the day.

In winter/autumn you may require a bit more time in the sun, particularly in the UK.

For most people, going for a 20-30 minute walk outside with your face and arms uncovered should be enough.

Take a vitamin D supplement

You can also take a vitamin D supplement or a multivitamin containing vitamin D.

Look for supplements that provide at least 400 IU per day (ideally 800 IU).

Eat a diet high in vitamin D

Finally, you can adjust your diet to incorporate more foods high in vitamin D. Some of the best options include:

• Salmon
• Cod liver oil
• Tuna
• Eggs
• Mushrooms
• Milk that has been fortified with vitamin D
• Cereals or oatmeal that has been fortified with vitamin D