Vitamins UPDATES

Food Fortification —

In the British Journal of Nutrition there is a commentary and an article on the benefits of this in Ireland.

Micronutrient malnutrition is a prime cause of ill health, iron , zinc and vitamin A and D , vitamin C and Vitamin B2 being prime examples.

Obviously a sufficient healthy diet is the answer which is not always seemingly possible. An alternative is food fortification. This ensures automatic delivery to the population. The poor are the most likely to benefit from this programme. It is sad to say often it is the less intellectually endowed who are the most at risk. This process has been applied for over 80 years.

The fortified food must be available to all parts of the population. , rich and poor
Where micro nutrient deficiency is extreme fortification is no substitute for the prime supplement in higher dosage
Supplements are less good when infection increases the need for the supplement.
The supplementation must be feasible in the local commonly eaten foods, e.g. flour, breakfast cereals and margarines
Supplementation may be given in foods eaten by particularly at risk populations e.g. children and the elderly.
Manufacturers might add supplements as part of the processing of the foods, within government regulatory limits.
Fortification is regarded as voluntary when the food industry freely chooses to supplement a micronutrient
It is important that the Government supervises the supplementation.
The range of foods which are allowed to be fortified may be quite narrow.
The stability of the micronutrient in that food during cooking is an important consideration
In Ireland of 3000 foods surveyed, 1.9% were fortified, mainly breakfast cereals. Fortification makes a significant contribution to the intakes of micronutrients for riboflavin, folate, vitamin D and iron. Calcium and vitamin D are worthy of consideration.

Rosenberg I 2007, Further evidence that food fortification improves micronutrient status Brit Journal of Nutrition 97, 1051-1052

Hannon EM et al 2007, The impact of voluntary fortification of foods on micronutrient intakes in Irish adults 97, 1177-1186

In the BMJ 2007 vol 334, pp 1252-3 the advisability of supplementing folic acid to foods is considered and whether this should be mandatory.

Wald NJ and Oakley GP argue for fortification. The less well off have the most to gain. The reduction in neural tube defects justifies the case. Supplementation must precede conception. There is a possible debatable reduction in cardiovascular disease and reducing the rate of cognitive decline with age. Maybe reduce the incidence of colon cancer. There is the threat of undiagnosed B12 deficiency and neurological consequences. This is unlikely at the dosages used. Synthetic folic acid is more biologically available than natural folic acid and is stable during cooking.

Hubner and his colleagues disagree. The metabolism and action of synthetic folic acid may not be similar to natural folic acid. They refute the protective effects of synthetic folic acid and suggest that the answer is natural folic acid.

They claim that there is an increased rather than a decreased risk of cancer with supplementation. The supplement promoting the growth of premalignant lesions and facilitating their conversion to a malignant process.

Which indicates that improving food intake is best and that governments should concentrate on nutrition

Nutrition Supplements and Drugs —

Nutritional supplements: prevalence of use and contamination with doping agents

In a review article by van Thurne and colleagues they discuss the role that nutritional supplements play in the lifestyle of a substantial proportion of the population

In addition to vitamins or minerals products, several precursors of anabolic steroids are marketed as nutritional supplements. Another group of commercially available supplements are products for weight loss based upon herbal formulations originating from Ephedra species.

Whilst some supplements indicate the presence of these active compounds, numerous non-hormonal nutritional supplements are to be found that were contaminated with non-labelled anabolic steroids. Stimulating agents other than naturally occurring analogues of ephedrine were detected

. A major group using dietary supplements are sportsmen, ranging from amateur level to elite athletes. Besides the possible health risks associated with the use of dietary supplements, athletes should take care not to violate the rules of the World Anti-Doping Agency

The responsibility for knowing what is in these supplements lies with athletes. They remain responsible for substances detected in their biofluids, irrespective of their origin.

The consequences of failing to do this are dire. The drug testing system is now very efficient. Or appears to be.

W. Van Thuyne et al 2006,Nutritional supplementation :prevalence of use and contamination with doping agents. Nutrition Research Reviews vol 19 , 147-158

Sun and Adverse Effects —

It is approaching the summer. Anticipation is increased by the clocks going forward

The sun for nutritionists is associated with increased vitamin D metabolism and other benefits and also a sense of well being. There is the down side of potential skin malignancies.

A further down side is the suicide rate in people who work out of doors. This is in part seasonal affect disorder but also there is a sense of despair in poor areas of the world with hopeless poverty. Also in women being forced into humiliating roles as a universal support. In many rural communities suicide is by the use of pesticides and it is estimated that there are 300,00 deaths a year using this method.

Another important source of suicide is alcoholism and this is a real problem in sportsmen. The prevalence of suicide in Cricketers is more than in the general population and may as in other sports be a consequence of alcoholism.

Synthetic Folic Acid and Anaphylaxis —

Food fortification with folic acid is the vogue. As nutritionists we must wonder why long term watching of folic acid dietary intake is not enough

In the Lancet 2007, Smith et al report a case of a woman who had well documented anaphylactic responses to 5 mg of synthetic folic acid

This is rare and may be related to the synthetic folic acid acts as a hapten

This is very rare but worth watching for.

Vitamin A Dosage And Prevention —

Vitamin A deficiency is a worldwide nutritional problem. The wellbeing of millions of babies and infants and mothers are threatened by this deficiency ( calculated to be 127 million ) and 7 million pregnant women. .

Most developing countries provide vitamin A supplements to infants and new mothers according to WHO recommendations. However, in 2002, the International Vitamin A Consultative Group recommended a higher dose of vitamin A. Momodou Darboe and colleagues ( Darboe et al 2007, effectiveness of an early supplementation scheme of high-dose vitamin A versus standard WHO protocol in Gambian mothers and infants: a randomised controlled trial designed a randomised controlled trial Lancet vol 369 pp 2088-96 ) ( 25000 IU v three doses of 50000 IU) to assess both dosing regimens.

No significant differences were noted for primary outcomes—

maternal vitamin A concentration at 2 months;

infant vitamin A at 5 months;

H pylori infection at 12 months;

maternal pneumococcal carriage at 12 months;

infant pneumococcal carriage at 12 months;

and infant gut mucosal damage at 12 months.

The investigators concluded that they saw no additional benefits of the high-dose regimen and recommend that the WHO regimen should not be changed.

In a Comment, Bernard Brabin Lancet 2007 Infant vitamin A supplementation : consensus and controversy pp 2054-56) discusses the controversy surrounding the selection of the optimum dose. The higher dosage raises concerns about overdosage.

Vitamin B12 Biosynthesis —

Vitamin B12 is a complex molecule synthesised solely by bacteria. The chemistry of B12 proved to be a difficult task and during the elucidation of its chemistry and biochemistry four Nobel prizes have been won. One fragment of the vitamin has defied understanding until recently ( Ealick and Begely Nature 446, 22nd March 2007 pp 387-8 ). This is the dimethylbenzimidazole ligand. ( DMB). reaction

There are several structurally related compounds of B12, only two have major recognised biological activity, methyl cobalamin ( a methyl donor in methionine biosynthesis ) and 5-deoxyadenosylcobalamin ( Ado B12) which is the source of the adenosyl radical, important in catalysing reactions with the removal of a hydrogen atom from a compound.

Ado B12 is the only organometallic compound used by living systems. The biosynthesis of which requires the destruction of vitamin B2., riboflavin. The enzyme is a flavin destructase ( BluB) , a reaction requiring oxygen. The enzyme catalyses the conversion of reduced flavin mononucleotide ( FMN ) to dimethylbenzimidazole ligand. ( DMB). The cannibalisation of one vitamin to create another, an interlinking system.

The writers of this fascinating article are surprised that this happens. But biochemistry is about the destruction of one chemical to form another. The fact that a vitamin is lost surely underlines why we have to continuously to stock up with more of the vitamin. .

Vitamin D and Sunscreen Protection —

Many people use sunscreens to protect themselves and their children against the most lethal effects of UVR. Unsettlingly, data so far have failed to show that the use of sunscreen protects against melanoma, the deadliest form of skin cancer (see page 851). This and associated controversies have produced responses tanging from deep epidemioiogical curiosity to a recently filed class-action lawsuit against the sunscreen industry83.

Sunscreens are widely used as protection against developing skin cancers. The evidence for protection against melanoma is as yet to be proven. With keratinocyte-derived skin cancers such as squamous-cell carcinoma are, the association between Ultra Violet Radiation and carcinogenesis has been clearly established Correspondingly, sunscreens, when applied correctly, are effective at reducing the incidence of squamous-cell carcinoma and its precursor.

Sunscreens are defined according to ‘sun protection factor’ (SPF), which is measured by calculating the minimal dose of UVR necessary to cause confluent redness at 24 h after exposure on protected skin compared with unprotected skin. At present, the SPF measurement is based mainly on protection against UVB radiation (wavelengths 290-320 nm), although newer sunscreens may also shield UVA radiation (wavelengths 320-400 nm). UVB can cause DNA damage, and there is growing evidence that UVA might also have carcinogenic effects8″. Another question raised is whether sunscreen inhibits vitamin D production. However, there is little evidence to suggest that sunscreen prevents adequate vitamin D production, or that low vitamin D levels are associated with increased melanoma risk.

Nature, vol 445 22nd Feb 2007 p846.

Vitamin D Dosage —

The American Academy of Pediatrics has recommended doubling its recommended dose of vitmin A for infants, children and adolescents to 400 IU daily. Clinical trials show that this dosage gives protection against rickets, boosts immunity and reduces osteoporosis in later life.

Vitamin D, Health and Adversity —

Susan Mayor in the BMJ 12 JANUARY 2008 VOLUME 336 page 62

Vitamin D deficiency is associated with bone disease .

Two recent studies show that lack of the vitamin D also increases the risk of heart disease and is linked to poorer prognosis for some cancers.

A follow-up study of 1739 offspring of the original participants in the Framingham heart study, with no cardiovascular disease, showed that those with low concentrations of vitamin D (below [5 ng/ml) had twice the risk of a first cardiovascular event, such as a myocardial infarction, heart failure or stroke, over a five year period than those with higher concentrations Wang et al in Circulation. After adjusting for the usual cardiovascular risk factors, high cholesterol concentrations, diabetes, and hypertension, the risk of a cardiovascular problems remained 62% higher in people with low vitamin D concentrations

A second study by Moan et al in Proceedings of the National Academy of Sciences of the United States of America shows that warnings to avoid sunlight because of the risk of skin cancer from solar radiation may have to be balanced against the health benefits of exposure to sunlight, given that vitamin D improves outcomes in patients with major internal cancers, including prostate, breast, and colon cancers.

The study showed that vitamin D production generated by solar radiation was 3.4 times greater in countries south of the equator than in the United Kingdom and 4.8 times greater than in Scandinavia. Although the incidences of major internal cancers were higher in countries at lower latitudes, the survival prognosis improved significantly.

Wang et al Vitamin D Deficiency and Risk of Cardiovascular Disease.

Circulation. 2008 Jan 7;

Moan, et al 2008 Addressing the health benefits and risks, involving vitamin D or skin cancer of increased sun exposure. Proceedings of the National Academy of Sciences of the United States of America vol 105: 668-673;

It would be an interesting thought that the absence of heart disease and cancer attributed to dietary fibre was in part a consequence of sun light and vitamin D production.


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