Vitamin D – The Sunshine Vitamin

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Vitamin D, or the sunshine vitamin, is actually not truly a vitamin but is actually a pro-hormone (an inactive precursor a hormone), which is made by the body when skin is exposed to sunlight. It can also be ingested from certain foods or dietary supplements.

The most well known role of Vitamin D is to signal the intestines to absorb calcium, but it also plays a part in controlling the immune system and has be shown to have many other benefits to health as well. Deficiency in Vitamin D is of worldwide concern with figures quoted of up to 50% of world population at risk. The Vitamin D Council believes that the level of Vitamin D in the blood required to give optimal benefit to health should be raised and if this were taken as the new benchmark then the figure would rise to 90% of the world’s population being at risk of Vitamin D deficiency.


During the Industrial Revolution, the diseases rickets and osteomalacia (now known to result from Vitamin D deficiency) first became prevalent in cities in both Northern Europe and the United States. The childhood disease of rickets had symptoms of weak bones, bowed legs and retarded growth and in adults osteomalacia caused severe pelvic bone deformity so pronounced that it necessitated a large increase in births by Caesarian section. Although it became known that exposure to sunlight and taking cod liver oil halted the progress of the diseases, it wasn’t until the early 1900s that the Vitamin D factor was identified in cod liver oil. For many years the recommended daily intake of Vitamin D was set at 100 International Units (IU), the minimum required to prevent these diseases.

In the mid 1990s, a few scientists began looking more closely at Vitamin D and its importance for our wider health. They investigated what might be the optimal level of Vitamin D for health rather than just the minimum required to prevent the deficiency diseases. A major critical analysis of benefits to health and potential toxicity was undertaken, with contributions from highly respected scientists and there is much more known now about Vitamin D.

Benefits to health

One of the longest recognised benefits to health of Vitamin D is that of bone health and reduction of fractures. The maintenance of calcium blood levels is essential for normal functioning of the nervous system, bone growth and bone density. If Vitamin D is low, the body will not be able to absorb enough calcium, no matter how much is consumed in the diet. So, to satisfy its need for calcium, it will begin to break down bones. A study of adolescent girls published in Arch Pediatr Adolesc Med online in March 2012 has shown that taking Vitamin D was associated with a lower incidence of stress fractures in those who participated in high impact activities but that calcium and dairy products did not affect the incidence of these fractures.

Rickets and osteomalacia occur because of Vitamin D deficiency and low Vitamin D over a long period of time contributes to osteoporosis by causing inadequate calcium absorption. Sufficient stores of Vitamin D may help prevent osteoporosis in older people, post menopausal women and those on long term steroid therapy.

There is a great deal of interest in Vitamin D’s effect on the immune system and the potential for it to boost the immune system to prevent infections such as influenza and tuberculosis or to prevent or slow the progress of autoimmune diseases such as diabetes, rheumatoid arthritis and multiple sclerosis. A study was carried out by Harvard Medical School over many years which found that those with low blood levels of Vitamin D had a significant 55% greater likelihood of getting a cold, influenza or other upper respiratory tract infection. Influenza is at its worst in the winter months and it has been proposed that the lessening level of sunlight is the seasonal stimulus to trigger the outbreaks. It is thought that Vitamin D also prevents the immune system from overworking, which can also cause problems and lead to complications such as pneumonia. It is suspected that this overworking actually caused many of the deaths in the 1918 influenza pandemic.

Studies on the geographical prevalence of the autoimmune diseases mentioned above have shown that cases increase as latitude increases and it is probable, therefore, that decreased exposure to sunlight and thus decreased levels of Vitamin D is linked to these diseases. There have been several studies which suggest Vitamin D intake decreases the risk of these diseases.

Recent studies have begun to show promising findings relating to prevention of certain cancers such as colon, prostate and breast amongst others. In fact, for decades it has been shown that higher exposure to sunlight can reduce deaths from cancer and, again, a geographical pattern has been noted whereby people who lived in higher latitudes such as the northern US had higher mortality rates from colon cancer than those who lived further south.

Vitamin D has a part to play in gut function and how flora in the gut maintain the digestive system. The “good” bacteria keep the “bad” bacteria down but without sufficient Vitamin D there is more inflammation and it is harder to fight off infection. Inflammatory bowel disease is another autoimmune disease that is thought that Vitamin D can help to inhibit.

Other benefits to health include:

  • Prevention of muscle weakness (including heart muscle)
  • Regulation of insulin activity
  • Regulation of blood pressure
  • Support for cognitive function, especially in the elderly
  • Support for mood stability, especially in the elderly
  • Prevention to some extent of chronic fatigue
  • Helping to slow the decline in breathing for asthmatics and COPD sufferers

Getting enough Vitamin D

It is entirely possible to get all the Vitamin D your body requires simply through exposure to sunlight. A short time outside two or three times a week is adequate to get your full quota. However, this is often not happening and there are many contributing factors such as:

  • Use of sunscreen/staying out of the sun to reduce risk of skin cancer
  • Age related decreases in Vitamin D synthesis
  • Women who cover all their skin when outside for cultural reasons
  • People with darker skin, particularly those who live further from the equator
  • Babies who are exclusively breastfed, especially if they do not get sun exposure or are dark skinned
  • Older babies and toddlers who are fed milk substitutes and diets not fortified with Vitamin D
  • Inflammatory bowel disease
  • Fat malabsorption syndromes
  • Obesity, because the fat soluble Vitamin D is stored in the fat stores and large stores of body fat make the vitamin less available to the body for use

Increasingly, lifestyles that tend towards being more sedentary and indoors are also contributing to this. Realistically, people find it hard to change their lifestyles and indeed, the other factors mentioned may be beyond their control. So generally people need to look to other sources of Vitamin D to ensure they are getting enough for optimal health. Vitamin D is present in foods such as fatty fish, eggs, red meat and liver. Some foods, such as dairy products and breakfast cereals can be fortified with vitamin D. However, sources such as the Vitamin D Council maintain that there is insufficient Vitamin D in foods and other than sunshine, the only way to increase Vitamin D intake is through supplementation.


There are two types of supplements available; D2 and D3. Vitamin D3 is the recommended supplement as it is the same substance that is synthesized by human skin, whereas D2 is not naturally present in the human body and may have some different effects. Vitamin D has cofactors, which are nutrients that affect the absorption of Vitamin D, and these are calcium, magnesium, Vitamin K, Vitamin A, zinc and boron. In particular it is recommended to take Vitamin D in association with calcium and magnesium and some sources suggest taking it with some fat, such as a spoonful of peanut butter, as it is a fat-soluble vitamin.

Although there is always a need for more research, there is a lot of evidence already collated that shows that Vitamin D has a very important role to play, not just in maintaining healthy bones, but for many more complex health systems. Although much of the work is in its infancy, it is clear that we need to work a little harder at ensuring we get enough Vitamin D to stay in good health.

Dr Tim and the Total Health Chiropractic team recommend that everyone supplements their Vitamin D3 and we recommend Lamberts which is available from our clinic. It is very inexpensive and the perceived benefits are enormous. This is the product that Dr Tim himself provides for his family.

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