Positive Health Online

When I began nutrition studies in the mid-1980s, vitamin D was dismissed quite quickly: Health? Bones. Diseases of deficiency? Rickets, osteoporosis. Symptoms of mild deficiency? Possibly bone pain, deafness, muscle weakness. Sources? Sunlight, liver, dairy fat. Toxicity? Easy to overdose as it's not easily excreted. Since then I thought little about vitamin D and assumed that all was well if it was present in a multivitamin product.

How wrong I was. Recent research suggests that vitamin D could be the key to food intolerances. It has been estimated that at least 30% of all patients who consult a family doctor are suffering from symptoms of food intolerance. Such symptoms range from chronic sinusitis, glue ear, asthma, headaches, ADHD (hyperactivity), water retention and eczema, to arthritis (osteo- and rheumatoid) chronic fatigue, irritable bowel syndrome and colitis. Discover and take away the problem food(s), and in vast numbers of cases all these problems simply melt away.

As a sufferer of food intolerances myself, I had become resigned to avoiding several staple foods. The price to pay for eating them was just too high: dairy products would bring on rheumatoid arthritic symptoms in my spine and fingers. Wheat and rye caused an aching, fuzzy head and the desire to sleep ten hours a night. Eggs caused a rapid pulse and palpitations.

What Makes Foods Produce Symptoms?

Many people have a slightly 'leaky' gut, which allows particles of partially digested food into the bloodstream. (For causes of leaky gut, see my book Treat Yourself with Nutritional Therapy.) Antibodies attach themselves to the particles, and this signals white cells called macrophages to swallow them up. Activated macrophages produce chemicals called cytokines, which tell the immune system to go into inflammatory mode. This is designed to get rid of foreign invaders and foreign particles (such as gluten) in the tissues. If the foreign matter can be removed, the cells which produce the cytokines should then die. If the cells do not die then chronic inflammation sets in. The severity of the inflammation depends on the prevalence of the different types of cytokines. It can range from long-term water retention and weight gain to tissue destruction, which manifests as arthritis, emphysema, kidney disease, Crohn's disease, multiple sclerosis and even Alzheimer's disease.

Vitamin D and Cytokines

One of the amazing new discoveries about vitamin D is that when it is lacking, cytokine-producing cells do not die as they should. They just go on producing cytokines. The research which led to this remarkable discovery stemmed from trying to find out why multiple sclerosis – nerve sheath destruction caused by chronic inflammation – rarely seems to occur outside northern latitudes where we get little sun and little vitamin D.

The implications are massive. Not only could we potentially wipe out multiple sclerosis and related diseases of chronic inflammation in the UK, northern Europe and North America, but we could perhaps prevent a large proportion of chronic ill-health currently caused by food intolerances.

When I discovered this research report I was already taking a daily multivitamin containing vitamin D, but I decided to try an experiment, and began taking two daily capsules of cod liver oil*, which provides vitamin D in its best, most useable form. The first benefit (which I experienced within two weeks) was less backache. The second benefit is that I no longer get drowsiness and headaches when I eat gluten. I seem to get no more rheumatoid symptoms from eating dairy products. I can also tolerate eggs occasionally, though if I try to eat them every day I begin to feel unwell. Maybe this will change as it is early days yet.

There is More to Vitamin D than Preventing Rickets

It seems likely that most of us in the UK are at risk of vitamin D deficiency, especially if we are health-conscious and avoid full-cream milk, butter and full-fat cheese. Liver has become unpopular as a food due to health scares about its vitamin A content. As a nation (especially our elderly people and those in nursing homes, prisons, etc.), we spend a lot of time indoors, and when we go out in the sun we cover ourselves and our children with sunscreen products. We live in a country where for much of the year the sun does not have the strength to help us make vitamin D.

Recommended Daily Allowances for Vitamin D may be enough to prevent rickets in children, but it seems increasingly likely that what is enough to prevent rickets may not be enough to maintain a normal immune system.

References

Munger KL, Zhang SM et al. Vitamin D intake and incidence of multiple sclerosis. Neurology. 62(1): 60-65. 2004.
Reported in Bland J Functional Medicine Update. Institute for Functional Medicine. Gig Harbour. Washington. USA. August 2004.

* If you decide to take cod liver oil, use a purified brand to avoid becoming contaminated with dioxins and other pollutants that become concentrated in fish liver.