Vitamin D has recently been the subject of various media articles and documentary programmes on television.
Vitamin D is a fat soluble steroid hormone and has wide-reaching, significant effects on more than 1,000 genes- Kathryn Borg
It has been said to be a ‘political hot potato’ in some European countries and a plethora of studies have flooded our research journals. Essentially there is an information overload.
Most people associate vitamin D with the childhood bone disease of rickets. Rickets is a softening of bones in children due to deficiency or impaired metabolism of vitamin D, magnesium, phosphorus or calcium, potentially leading to fractures and deformity.
This disease is among the most frequent childhood diseases in many developing countries. The predominant cause is a vitamin D deficiency, but lack of adequate calcium in the diet may also lead to rickets.
Although it can occur in adults, the majority of cases occur in children suffering from severe malnutrition, usually resulting from famine or starvation during the early stages of childhood.
Osteomalacia is the term used to describe a similar condition occurring in adults, generally due to a deficiency of vitamin D. The origin of the word ‘rickets’ is probably from the old English dialect word ‘wrickken’, to twist.
The Greek-derived word ‘rachitis’ (inflammation of the spine) was later adopted as the scientific term for rickets, due chiefly to the words’ similarity in sound. Symptoms of rickets include bone pain or tenderness; dental problems; muscle weakness; increased tendency for fractures; skeletal deformity; toddlers: bowed legs; older children: knock-knees; cranial, pelvic, and spinal deformities and growth disturbance.
As such this disease has not been seen in the Western world for decades. However, like some ancient diseases mainly due to poor nutrition, it is starting to be diagnosed in small numbers. Once again this is mainly due to lifestyle.
Vitamin D is a fat soluble steroid hormone and has wide-reaching, significant effects on more than 1,000 genes. This means it acts on cells in every organ of the body.
The predominant natural source of the vitamin is the sun; hence, in sunny climates such as Malta one would think it unnecessary to be concerned about our vitamin D levels.
The only significant food source is oily fish such as mackerel, fresh tuna, salmon and fresh sardines. However, new lifestyle concerns have changed our habits and many people are not absorbing what they require from the sun.
Certainly in the UK the population cannot get what is required from the sun due to the bleak weather. In fact, those in the north of England do not even absorb vitamin D in the summer, never mind the rest of the year.
Also, the sun needs to be absorbed all year round; it cannot be stored in the summer for use in the winter. This situation is causing such concern to some experts that they are calling for vitamin D deficiency to be classified as a major ‘lifestyle’ risk along with smoking, alcohol, obesity and lack of exercise.
Some of the diseases that an insufficiency of vitamin D can cause are osteoporosis, muscle weakness and falls, cancer, cognitive disorders, seasonal affective disorder, immune system problems and cardiovascular disease.
Unfortunately, in setting public policy, countries such as the US and UK have focused primarily on bone health and have not taken into account vitamin D’s many other roles in the body.
In the UK they have concentrated on the elderly, babies and young children who have, in certain circumstance, been prescribed a low dose of vitamin D. However, as we will see, the current lifestyle habits include all age groups in the population.
The sun’s rays are the key to a successful uptake along with a good food source. Many people do not eat fish, especially oily fish, on a regular basis, if at all. In addition, the general guidance regarding sitting in the sun has the power to totally eliminate the uptake of any sun’s rays and convert to vitamin D in the body.
There are many factors affecting uptake from sunlight. The season, the latitude, time of day and cloud cover. For example, complete cloud cover reduces vitamin D synthesis by 50 per cent. In addition, sun cream with an SPF of +8 will seriously affect the uptake of vitamin D.
Additionally, certain medications can interact with the uptake of vitamin D. Steroids, for example, can impair vitamin D absorption as can some epilepsy and weight loss drugs.
The habit of covering our bodies when out walking in the sun, even moderate sun, has blocked any chance of uptake, as has the tendency to travel everywhere by car and walk less.
A lifestyle conducted indoors rather than outdoors has not helped our exposure to the sun. The rays do not penetrate glass, clothes or sun cream over factor 8.
Children spend more time inside, adults tend to shut out the sun and many people avoid eating fish. Over a number of years this all adds up to a serious vitamin D deficiency.
In conclusion those affected are always the elderly and children. Also affected are people with pale complexions, those who use copious amounts of sunscreen, those in cultural dress, such as those covering themselves from head to foot, office staff working from morning to evening without venturing outside, those who are housebound, those suffering from gastric surgery or with liver/ kidney impairment. Additionally, vegans, vegetarians and those suffering from epilepsy are at risk too.
For further technical information, Robert Heaney presented the Vitamin D and breast cancer symposium on March 23 this year. His presentation is available at www.grassrootshealth.net/media/download/heaney_vit_d_deficiency1110.pdf.
kathryn@maltanet.net