Health supplements information service

Citation

(2009), "Health supplements information service", Nutrition & Food Science, Vol. 39 No. 2. https://doi.org/10.1108/nfs.2009.01739bab.021

Health supplements information service

Article Type: Food facts From: Nutrition & Food Science, Volume 39, Issue 2.

A study published recently in the Journal of the American Medical Association reviewed a group of American male physicians and the relationship between the intake of vitamin C and vitamin E and reduced the risk of major cardiovascular events.

Commenting on the study, Pamela Mason, spokesperson for the Health Supplements Information Service (HSIS) notes: “Vitamins C and E are essential for human health and given that dietary intake of these vitamins is low in some groups of the population in the UK, supplements containing vitamins C and E can help to bridge these dietary gaps and can safely be consumed in accordance with recommended dietary allowances.”

“This study was a ten-year randomised placebo-controlled trial in which participants were given 500mg of vitamin C every day and 400IU of vitamin E every second day. The cardiovascular events being monitored were nonfatal myocardial infarction, total stroke, cardiovascular death, congestive heart failure, total mortality, angina, or coronary re-vascularisation.”

“There was no difference between vitamin E or vitamin C and placebo in terms of major cardiovascular events and individual cardiovascular events, include myocardial infarction (heart attack) and stroke. There were also no differences in rates of congestive heart failure, cardiovascular mortality or total mortality. However, vitamin E was associated with an increased risk of haemorrhagic stroke. Whether or not the men had cardiovascular disease made no significant difference to the results.”

“This is yet another trial evaluating the effect of vitamins in risk of cardiovascular disease. However, vitamins are essential nutrients that act to maintain health and prevent vitamin deficiency. They were never intended to be used to prevent cardiovascular disease or any other chronic disease. Indeed, it would be asking a lot of a vitamin pill to expect it to prevent cancer.”

So why are vitamins E and C essential for health?

Both vitamins E and C have a number of essential functions in the body. Vitamin E is a fat-soluble vitamin whose main role is as an antioxidant. It protects body cells from toxic compounds, heavy metals, such as lead and cadmium, and also from the effects of drugs, radiation and free radical damage. It works in fats and oils, which make it complementary to vitamin C, which fights free radicals dissolved in water. Free radicals can harm cells, tissues and organs.

As an antioxidant, vitamin E helps to protect the fats in low density lipoproteins (LDLs). Lipoproteins are substances that transport fat and protein through the bloodstream. LDLs specifically transport cholesterol in the blood. If oxidised, LDLs deposit cholesterol in the blood vessels so causing build up of fat and damage to blood vessels. If LDLs are not oxidised, this helps to maintain the health of the blood vessels.

Vitamin E makes an important contribution to the health of the heart, blood and blood vessels. It helps to maintain the blood at an appropriate consistency – not too sticky – by an action on platelets, which are one type of blood cell. Vitamin E also helps in the formation of red blood cells. All of these effects help to maintain appropriate blood flow in the circulation.

Vitamin E has several functions not directly related to its antioxidant activity. Thus it has an effect on the activity of substances such as proteins and enzymes that work in immune and inflammatory cells. This action helps to maintain the health of the body's immune and inflammatory systems. Vitamin E also helps to regulate the activity of some of the substances in the body that send signals between cells. This is another function of vitamin E that helps to maintain the health of the body's cells.

Low and marginal intakes of vitamin E are not uncommon in the British population. There is no Reference Nutrient Intake in the UK for vitamin E but the EU Recommended Daily Amount is 10mg daily. In the National Diet and Nutrition Survey (NDNS) in British adults aged 19-64 years, 47 per cent of men overall and 67 per cent of women overall had a vitamin E intake below 10mg daily. In the 19-24 year olds, these figures increased to 60 per cent men and 76 per cent of women.

Vitamin C is a water-soluble vitamin. Like vitamin E, it is an effective antioxidant. Vitamin C can protect essential substances in the body such as proteins, lipids, carbohydrates and DNA and RNA from damage by free radicals. Vitamin C works in tandem with vitamin E and is able to regenerate vitamin E when vitamin E is used as an antioxidant. Vitamin C is also required for the synthesis of collagen, an important structural component of blood vessels, tendons, ligaments and bone. Vitamin C plays an important role in the regulation of various neurotransmitters, including norepinephrine and acetylcholine, which are critical for brain function. Vitamin C is also required for the synthesis of carnitine, a substance essential for the transport of fat to the body's cells for conversion to energy. Vitamin C is also involved in the metabolism of cholesterol to bile acids and protects LDL cholesterol against damage. The vitamin is also important for the absorption of iron from plant foods (cereals, nuts, fruits, vegetables, pulses).

Evidence suggests that vitamin C plays an important role in the human immune system by protecting various types of cells, such as phagocytes, lymphocytes and neutrophils, within the immune system.

As is the case for vitamin E, low intakes of vitamin C are quite common in the British population. In the NDNS in British adults, vitamin C intakes were below the Reference Nutrient Intake in 21 per cent of men and women. This increased to 25 per cent in the 19-24 year old group. In people over the age of 65, vitamin C intakes were below the RNI in 28 per cent of free living men and 36 per cent of free living women.

It can be seen that significant dietary gaps do exist for vitamins E and C. Supplements can help to make up dietary gaps caused by poor diets, which are a problem for significant numbers of people in this country young and old.