Monday, November 4, 2013

Vitamin D Needed to Fight Comeback of Childhood Rickets

Wrist X ray Showing Changes in Rickets, mainly...
Cupping caused by Rickets (Wikipedia)
by Peter McCaffery, University of Aberdeen

For most people, our standard diet provides all the necessary vitamins we need.

However, childhood vitamin D deficiency in the UK - something that should be a headline from the distant past - has made a comeback.

And with that has come a rise in cases of rickets, a disease in which the bones become soft, weak and can become deformed without essential calcium.

Sally Davies, England’s chief medical officer, has called for all children under five (not just those from low-income families) to be offered free supplements.

We need vitamin D to effectively absorb calcium and phosphorous and to move these chemicals around the body and provide such essential elements for bones and teeth. Fat-soluble vitamin D is found in oily fish while smaller amounts are present in eggs and dairy products.

Counter to what you may think of a vitamin as an essential nutrient, vitamin D can be made by the body. This is where the “sunshine vitamin” moniker comes from since it is made in the skin on exposure to the UV spectrum of sunlight.

Unfortunately, we don’t live in the Sunshine State - and in the UK we only really make vitamin D from skin exposed to sunlight in the middle of the day from April to September when ultraviolet light is strong enough.

Getting out into the sun two to three times a week for a few minutes without suncream can give you enough vitamin D to last you a year. But on the whole we are very dependent on diet for our vitamin D. And a severe lack of it causes rickets.

The return of a ‘Victorian’ disease

One of the best early description of rickets came in 1644 from Daniel Whistler, a Cambridge doctor. Unfortunately it wasn’t as accurate on the cause, suggesting a “paucity of and stupefaction of spirits”.

Some 200 years later, without a more useful understanding of its cause and in the rapidly growing industrialised and polluted cities in the west, a large proportion of infants of the underprivileged showed signs.

Some realised that something was missing in the diet because people living in coastal areas found that cod liver oil provided protection.

And in the early 20th century, the study of the individual chemical components of cod liver oil revealed a lipid they named vitamin D. Now that the cause was known, widespread supplementation was used to almost wipe out the disease.

Jeremy Allgrove wrote on past resurgences of nutritional rickets in the UK in which he observed an increase, several decades ago, in immigrants from the West Indies and the Indian subcontinent.

People with higher pigmentation in their skin, which provides protection from UV, are unfortunately worse off than those with paler skins when it comes to making vitamin D in low-light conditions.

Of course this was even worse in northern areas of the UK such as Scotland; however this was dealt with effectively in areas like Glasgow by use of low-dose vitamin D supplements.

But now cases of rickets are creeping back in children. It seems to have been forgotten that diet does not necessarily provide sufficient vitamin D for the growing body, especially during winter months.

Research in Birmingham found a 7.5% incidence of vitamin D deficiency in children. While, in 2010, there was an incidence of the disease in Southampton.

An astonishing 32% of children showed vitamin D insufficiency and 8% had full deficiency. This was among not only poorer children but also middle class ones.

The UK isn’t the only developed country that has seen incidents of rickets. A study in Boston, Massachusetts, also found deficiency in the seemingly healthy young and noted other incidences across the US.

Reasons point to deficiencies in diet and skin pigmentation in some cases, but also the use of suncreams - which also prevent skin damage and cancer. So something classified by the average GP as a disease of the Victorian era, is now back among children.

Battle cries and benefits

The battle cry against this upsurge is being led by Davies. Her report on the health of the young in England makes for some grim reading. English children are not well when compared to top countries such as Sweden - and they show higher mortality, morbidity and inequality.

One of the report’s many recommendations includes better nutrition. And among the proposals, Davies has asked health regulator NICE to determine whether vitamin A, D and C supplements should be provided.

These are already available on the NHS for children from families on welfare benefits, but the idea will be to make them free to all children between the ages of six months and five years.

It also discusses how these supplements helped to combat the resurgence of rickets in Birmingham. The lives of many children can be helped easily and cheaply by keeping it simple, and doing it now.

But why are vitamins A and C mentioned in Davies' report? This is a great surprise as there’s no evidence for a current deficiency in these vitamins. Just because children are deficient in D, doesn’t mean they are deficient in A and C.

To ensure the success of Davies’ idea, we must consider the data and stay focused. Treat the growing incidence of vitamin D deficiency in children and leave the other vitamins alone.

This isn’t a time to panic, or to pay for unnecessary, and potentially harmful, supplements. There is the need though for vitamin D supplementation in those children who are deficient.

This shouldn’t be confused with the case for adults, or whether vitamin D supplementation is necessary beyond eating well.

These separate questions continue to be debated and researched - but don’t hold your breath for a definitive answer anytime soon.

Peter McCaffrey receives funding from the Biotechnology and Biological Sciences Research Council (BBSRC)
The Conversation

This article was originally published at The Conversation. Read the original article.
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