The ‘sunshine hormone’ – Vitamin D

The ‘sunshine hormone’ – Vitamin D

Lighter, Brighter Your Blog: The 'sunshine hormone' - Vitamin D

Vitamin D can be made, or synthesized, by your body when it is exposed to sunlight. Your body makes vitamin D through the action of sunshine on the cholesterol that is present in your skin. This means that it is not technically a vitamin, because vitamins are classified as compounds that our bodies cannot make and which we have to get from our food. Therefore, some researchers call it a hormone instead, as it is similar in structure to some of the main hormones in our bodies, such as estrogen and cortisol, and it performs hormone-like activities too.

What does vitamin D do in your brain?

Vitamin D is involved in the development and maturation of neurons, as well as regulating the growth of the specialized cells that support the neurons, called glial cells.

It is involved in the genetic expression on a variety of neurotransmitters, like dopamine and serotonin.

Vitamin D is involved in brain metabolism as well as in a structural role, with vascular and volume changes being noted in animal studies in the presence of vitamin D deficiency,

May prevent specific inflammatory pathways that lead to neurodegenerative disorders like Alzheimer’s disease.

A lack of vitamin D may increase the risk of cognitive decline via this mechanism.

A lack of vitamin D is associated with diseases such as cardiovascular disorders (CVD) and diabetes, conditions which often lead to reduced cognitive function and mood disorders.

Vitamin D may act as an antioxidant in the brain, offering protection against cognitive decline, including dementia.

Global cognitive performance in older adults is associated with vitamin D status.

Vitamin D plays an important role in brain development, which may lead to both physiological and psychological impairments in offspring whose mothers were deficient in this vitamin.

What does vitamin D do in your body?

This vitamin is essential in the body for a number of reasons:

  • It is essential for the formation of healthy bones and teeth, as it helps the body to absorb, retain and use calcium and phosphorous
  • It has recently been found to be protective against getting cancer
  • It helps keep your immune system efficient
  • It may help to prevent high blood pressure
  • It may help to prevent Type 2 diabetes
  • It has a stimulating effect on specific substances in the brain, called neurotrophins, which regulate neuronal cells and their activity
  • Research into its effects on cognitive functioning has highlighted that low levels of vitamin D are related to low mood, and impairment in cognitive functioning
  • Low levels are involved in sleep disturbances
  • Low levels may also contribute to weight gain

Separating the myth from the facts

Researchers used to believe that you could make enough vitamin D if you simply have sun on your body for at least ten minutes a day. Recent research is contradicting this belief.

The reason this belief is changing is because the specific UV-B (ultra-violet-B) rays that act on your skin to produce this important vitamin, are dependent on a number of different factors, such as:

  • Where you live, which includes the latitude and altitude
  • The season
  • Whether there is pollution in the air
  • Whether there is cloud cover
  • Your skin color
  • Your age
  • Whether you are overweight

Your address may determine your vitamin D status

If you live in the Northern hemisphere, you may not very well be able to rely on the sun to give you your dose of vitamin D, so eating vitamin D rich foods, as well as supplementing with vitamin D is a good idea.

But, if you live in a warm, sunny country, getting 1–2 hours of sun exposure every day in the early morning or late afternoon, to avoid skin damage, is a good way to get adequate amounts of this important compound. Consuming foods that are high in vitamin D would be beneficial too. But, if you use sunblock when you are in the sun during harsh sunlight, you won’t be getting the benefits that the sun can provide. So choose the time with care.

Constant pollution and cloudy weather obviously decrease the amount of UV-B rays that reach you, so if you live in an environment where this is the case, supplementation is the smart thing to do.

Skin color affects your vitamin D status

Light skin makes vitamin D more easily than darker skin, because the sun's rays can penetrate deeper into light skin. So, darker-skinned people would need longer in the sun, as well as supplementation, to ensure adequate levels.

Getting older is also a factor

Unfortunately, as you get older, degenerative changes that can occur in your skin could make it more difficult for the cholesterol in your skin to help make vitamin D. This means that with increasing age, you may have to rely more on foods high in vitamin D, and supplementation, than on sunlight. And if your cholesterol levels fall too low, then this will also affect your skin's ability to make vitamin D.

Are you overweight?

Researchers believe that when you are overweight the vitamin D that you do have in fat cells, where it is stored, may be less available for use in the body. Being overweight may also interfere with the absorption and use of vitamin D-rich foods.

Sunscreen can hinder vitamin D production

If you use sunscreen with para-aminobenzoic acid (PABA) in it, be aware that it may interfere with your body’s ability to make vitamin D. Furthermore, your skin can't make this vitamin without direct exposure to the sun, so sitting in your car, or inside your home behind glass, will not result in any vitamin D production taking place in your skin.

Essential fats can help your skin make vitamin D

Being deficient in essential fatty acids (EFAs) will also impair your skin's ability to absorb and utilize sunlight. Daily supplementation with the right EFAs will ensure that your skin stays healthy, so it will be able to convert cholesterol to vitamin D efficiently. Consuming enough EFAs will also ensure that your skin is protected to some degree from damage due to sun exposure, as long as you act wisely in the sun, and avoid the harsh midday sun in mid-summer.

When you don’t have enough vitamin D, watch our for…

You may now be wondering whether you have enough vitamin D in your body? Signs of deficiency include muscle weakness or stiffness, backache, hair loss, anemia and a softening of the bones and teeth. Insomnia may also be related to a deficiency in vitamin D, and depression is now being linked to a deficiency too. Long-term deficiency in children results in rickets, a severe bone-softening disorder, where bones become prone to fractures and deformity.

Having a blood test done to assess what your vitamin D status is, makes sense, especially if you are unable to spend time in the sun regularly, or if any of the other factors mentioned above, apply to you.

The best test to request from your health care practitioner is called the 25(OH)D test, which is the acronym for serum 25-hydroxyvitamin D. If your results are less than 30 ng/ml then your doctor will suggest a supplement. Research indicates that levels between 50 and 100 ng/ml are optimal for healthy people.

As vitamin D is a fat-soluble vitamin, excess will be stored in your fat cells, so it has the potential to be toxic in large doses. It is therefore important to request a blood test, and assess the results with your doctor.

Which foods contain vitamin D?

Foods that are high in vitamin D include eggs, butter and fish, which is highest in this nutrient. The best plant source is cold-pressed vegetable oil. Unsurprisingly, sunflower seeds, whose flowers worship the sun's movement across the sky, are also high in vitamin D.

Fat helps the absorption of fat-soluble vitamins, like vitamin D, which is interesting, as nature has wisely provided this vitamin in the above foods, which also have a high fat content.

The best form of this supplement is …

This vitamin is made up of two components, vitamin D2, known as ergocalciferol, and vitamin D3, cholecalciferol. When choosing a supplement, choose one with the vitamin D3 component, as the body assimilates it much more efficiently than the D2 component.

Although many people choose to use cod liver oil as a vitamin D supplement, contaminants such as PCB’s, dioxins and heavy metals could pose a real danger in these products. Furthermore, the liver is the detoxifying organ for both you and the fish, and as most fish live in contaminated water today, their livers may not be offering up the safest form of vitamin D. Keep in mind that the harsh processes that supposedly remove the toxic chemicals from the fish livers, also pose a threat to the delicate fats that are present in this organ, and which you will consume when you use this type of supplementation.

There are both vegan and vegetarian forms of vitamin D available, as well as a few that are made using lanolin, a wax derived from the wool of sheep, that also contain vitamin D.


Aim to get into the sun and enjoy its health-giving properties regularly and safely, as well as the lovely feeling of vitality and health that you are left with after enjoying the sun's action on your skin on a sunny day. Now you know that the sun is actually helping your brain feel happier and stay healthy, so it’s not your imagination that a sunny day at the beach makes you feel good! And investigate your vitamin D status if you have some health issues that are of concern. Then, if you need to take a supplement, choose one with care. 


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