D-vitamin – The sunshine vitamin

Text Doctor Carsten Vagn-Hansen

Strictly speaking, vitamin D is not a vitamin since we create it in our bodies when the sun’s ultraviolet light of the UVB type hits our skin. Instead, it is a hormone and formation occurs in the surface based on cholesterol. For us to be able to create enough vitamin D3, the sun must be high in the sky and shine directly on our exposed skin. So the deficiencies are more common in the far north, where we can only get enough sun during the height of summer, and even then if we are not afraid to expose a lot of our pale Nordic skin to the sun.

The further north you go, the more necessary it is to get in your vitamin D from other sources, such as oily fish.


After vitamin D3 is formed in the skin, the bloodstream carries it to the liver where it is converted into the pro­hormone calcidiol. From there the journey continues to the kidneys and large white blood cells where it is converted into calcitriol, the biologically active form of vitamin D. Calcitriol is then transported around the body using a carrier protein in the plasma since most organs have vitamin D receptors.

During the dark winters of the north, most suffer low levels of vitamin D3 leading to an increased risk for a variety of diseases and ailments since a vitamin D3 deficit weakens the immune system. It’s best to make a habit of taking a dose every day, so you don’t forget.

The ideal level in the blood is at 107.5 nanomoles per litre and, for most people in winter that would correspond to a daily dose of 70 to 105 micrograms of vitamin D3. Vitamin D3 is fat-soluble, so it can be advantageous to take it in connection with a fatty main meal.

Remember that an intake of natural vitamin D3 is entirely safe and you can increase the dose by many multiples for a short time to fight, for example, influenza.


Knowledge about vitamin D affects the body’s organs, and functions have increased in recent times. If you want to prevent disease and boost your vitality, blood levels of the vitamin should be in the upper range of ‘normal.’ People with a chronic illness often have too little vitamin D3 in their blood. It is not just the body and its organs that need a supplement. The brain also needs a supplement of vitamin D3 since it helps with some types of mental illness.

From the very beginning of life, D3 is a crucial vitamin. The vitamin has a significant impact on the human ability to propagate and is essential for fetal development in the womb. Vitamin D3 strengthens both the fetus’ and mother’s skeleton because the vitamin is necessary for calcium absorption. Lack of vitamin D is prevalent in pregnant women, and too little vitamin D brings a fivefold increase in the risk of preeclampsia. Vitamin D intaking boosts the immune system in the placenta by stimulating the antibacterial peptides cathelicidin. In turn, it reduces the risk of inflammation and viral infections of the placenta.


Several scientific studies show that persistent musculoskeletal pain is often brought on by lack of vitamin D. A survey of 150 patients of both sexes with persistent musculoskeletal pain showed that 93 per cent of the subjects, regardless of gender, had low levels of vitamin D3.

Many other studies have also shown that a lack of vitamin D can lead to problems with pain in bones and muscles. For example, researchers in Saudi Arabia found a lack of vitamin D in a study of 360 patients with chronic back pain. All patients received high doses of vitamin D for three months and reported significantly reduced pain.

It, therefore, appears that anyone with chronic musculoskeletal pain should ask their doctor about measuring their vitamin D levels. Even young people are at risk if they suffer a vitamin D3 deficiency:  A Finnish study of calcidiol in adolescent girls showed that many had too little vitamin D3 in the blood, which, among other things, can increase the risk of osteoporosis in adulthood.


Vitamin D is also needed for the heart and blood circulation. Vitamin D3 prevents the oxidation of cholesterol, which in turn strengthens the heart, lowers blood pressure and works against atherosclerosis. Thirty-nine per cent of apparently healthy Danes have calcified coronary arteries and thus have at least a doubling of the risk of blood clots in the heart.

In general, vitamin D3 counteracts infection-like changes, called inflammation, that are the root cause of many diseases. Too low levels of the vitamin can also triple the risk of metabolic syndrome, the precursor to diabetes, and to improve sugar control in people with type 2 diabetes.


How long we live depends partly on our telomeres, which are parts of chromosomes that deteriorate with age. British researchers have shown that women with high levels of vitamin D in their blood also had longer telomeres, which means cells can divide more times, and the ageing process slows. Vitamin D3 strengthens bones, heart and muscles so that the injuries from falls can be avoided and you can live longer with a better quality of life. A study has shown that older people with high levels of vitamin D may postpone the need to go to an assisted living facility by as much as seven years.


Danish physician Carsten Vagn-Hansen spent 18 years as a general ­practitioner as well as being a lecturer and course leader for his country’s Practicing Doctors Centralized ­Continuing Education system. He was president­ of the International Society­ of General Medicine­ from 1979-1982. Also, he has received numerous awards, including The International Nature Medicine Honorary Prize. He is the author of multiple books on health and wellbeing. He is a former radio doctor on Denmark’s Radio and a television doctor on DR TV station.

Now he’s writing for EQ Magazine in addition to being a health consultant, speaker and self-proclaimed “travelling salesman for health.”

Read more on his website, RADIODOKTOREN.DK