SUPPLEMENTS - Natural versus Synthetic


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Almost one in three people take food supplements to enhance their diet, and for nutritionists, they are important tools of the trade. But vitamins can sometimes be derived from natural or synthetic sources, and arguments rage over which is better. So what’s the truth? Angela Dowden investigates.

In the early days, scientific studies were based on observations that food carried within it the power to heal. Brown rice was shown to cure symptoms later known as vitamin Bi deficiency, and in the early 1900s, scientists deemed a number of foods, such as milk, fruit and vegetables, to be protective against ill health.

At the same time, scientists started the search for the exact structure of the secret compounds within food, which helped people to get better from ill health. This isolation of specific nutrients was useful in two respects; nutritional research gained from the greater knowledge of the identity and function of vitamins and minerals within the body, and knowing the chemical structure of nutrients allowed methods to be devised for their man-made manufacture.

Today, the synthesis of vitamins is big business. Manufacturers have the ability to convert what may seem like unlikely starting materials into useful nutrients for supplement companies to use in their products. One of the most popular, vitamin C, is made using glucose, often derived from cornstarch or sago. Through an industrialised process involving a series of chemical reactions, sugar is converted into ascorbic acid. In most cases the only difference between the vitamin C products on our shelves is the combination of bioflavonoids, fruit extracts or metabolites added to give the formulation a nutritional and competitive edge.



When you think of the growing demand for supplements, it is easy to see why large-scale production of synthetic vitamins is required.

“Many natural vitamins are unable to meet the requirements of modern manufacturing in terms of volume, consistency and quality,” says Rosemary Sinclair of Roche Products (one of the worlds largest suppliers of nutrient raw materials to industry).

“Vitamins in their natural forms, tend to be sensitive to outside influences such as heat and light,” she adds. “Other factors, such as how soluble they are, their level of concentration and their physical form, restrict the way they can be used in foods, food supplements or cosmetics. Manufacturers who produce synthesised vitamins are able to modify their forms so that they are more stable and can be used for a variety of applications.”
Quite apart from these benefits, some vitamins just can’t be used effectively in their natural form. The main problem is that in the very act of extracting a vitamin from a food it may be destroyed in the process. Even if the vitamin does survive, the amount of a vitamin that can be fitted into a normal dosage form is very small.
“Pure, synthetic vitamins are far more concentrated than many natural forms of nutrients,” explains Steven Derrick of Cornelius, a major UK supplier of both synthetic and natural raw materials. “This is very important for tablet manufacture, as it keeps the size of the tablets down - a definite benefit.”

With the supplement industry under growing scrutiny over quality issues, it’s easy to see why synthetic vitamins win plaudits here too. Legally, products have to have a guaranteed potency, a guaranteed purity, and a guaranteed shelf life. With synthetic nutrients, which have a known profile, these aspects are easier to control.
Manufacturers are able to soften the blow of some synthetic nutrients by describing them as “nature identical”. These compounds blur the line between natural and synthetic because they are made according to the same processes, which would occur, in the body of a living animal. They also use natural substances (glucose in the case of vitamin C and cholesterol derived from Sheep’s wool in the case of vitamin D) as the starter substrate.
Suppliers of “nature identical’ nutrients claim that these vitamins have an identical form and function to those found in nature, but they are manufactured synthetically to extremely high standards. According to Sinclair: “Studies have established that the synthetic compounds are identical in all biological properties and activity of naturally occurring vitamins.”


But despite such confident statements, there has always been a healthy market for natural alternatives. Brewer’s yeast, for example has been recommended as a rich source of B vitamins for many years, and cod liver oil is a traditional way of getting the fat-soluble nutrients, vitamins A, D and essential fatty acids.
Over the last five years, other more sophisticated formulations have been swelling the ranks of natural supplements. Key among them are food state vitamins, which claim to reproduce all the benefits of nutrients complexed with a food.

“To simplify a complicated patented process, what happens is that the appropriate vitamin or mineral is introduced, at a controlled rate and temperature and with constant stirring, into a vessel that contains a fruit or yeast extract,” explains Eric Llewellyn, technical director of Nature’s Own. Over a period of hours the food - orange pulp in the case of vitamin C and yeast in the case of minerals - actually incorporates the nutrient within its cellular structure.”

Sophisticated identification techniques show that the nutrient is indeed properly incorporated within the medium and doesn’t just mix with it. But it is difficult to prove these bonded formulations are any better absorbed than say vitamin C with added bioflavonoids or a fully reacted mineral chelate.

A long drawn out court case allowed the US food state manufacturer that supplies Nature’s Own to describe their vitamins as ‘better’ but nearly bankrupted the company in the process. “No matter how much we spend on research the problem is that you simply aren’t comparing like with like, so someone is always going to dispute the results,’ says Llewellyn. “Practitioners find the products superior and we are happy with that.”

Despite this, the orthodox view is still that synthesised vitamins are identical to those found in food. But even hard- liners have to accept that there is a chemical difference between natural vitamin E (d-alpha tocopherol) derived from vegetable oils and synthetic vitamin E (d-alpha tocopherol) synthesised from chemicals.
‘Recent research shows that the human body prefers natural vitamin E making it up to twice as effective as synthetic,” says Anne Moore of Henkel, the world’s largest supplier of vitamin E.

In one study, researchers gave healthy, hospitalised and seriously ill patients equal doses of natural and synthetic vitamin E together. Blood levels of natural vitamin E were consistently twice those of the synthetic and the same pattern of retention occurred in various organs and glands.

In a recent research review of 30 studies published in the American Journal of Natural Medicine, Dr. Robert Acuff from the State University of Tennessee concludes that 9n the case of vitamin E, the natural form is clearly the one our bodies were designed to use”

Carotenoids are another area where natural forms are gaining popularity. Synthetic beta-carotene, also called all- trans beta-carotene’ has been on the market for many years. However, about five years ago, mixed carotenoids were introduced, and have made a positive mark on the supplement industry as a whole. ‘Mixed carotenoid supplements are extracted from algal species of the Dunaliella family, such as Dunaliella Salina. Rather than providing purely all- trans beta-carotene, Dunaliella extracts supply a good amount of the highly bioactive 9-cis beta-carotene, which is claimed to be a superior antioxidant.

In addition, Dunaliella Salina also provides alpha carotene, lutein, lycopene, zeaxanthin and cryptoxanthin. Each of these carotenoids has health benefits in its own right; for example, lycopene for prostate health or lutein for the eyesight.


For the majority of manufacturers and supplement users, synthetic vitamins are acceptable, cheap and meet a need for pure forms of specific nutrients. But there are times when people may be prepared to pay more for ‘natural’ methods of obtaining nutrients, which come ready packaged with synergistic and complementary nutrients. Many practising nutritionists find people with sensitive digestive systems, multiple allergies or toxic overload can particularly benefit from these formulations.

But no matter how close natural vitamins may be to the real thing, no supplement can fully mimic the profile and complexity of a truly balanced diet. For now, relying on real, wholesome, preferably organic foods is still the best way of getting the nutrition we need.

B vitamins are available from many sources in the diet, whole grains and cereals, meat, poultry and fish, milk, eggs and leafy green vegetables. Brewer’s yeast, which is often considered a ‘natural’ B complex formulation, is taken by many people to increase their daily intakes of B vitamins. However, many people want to avoid yeast products and do not want to take up to ten tablets per day. For these individuals, a synthetic B complex preparation is preferable.

Beta-carotene is found in foods such as carrots, sweet potatoes, broccoli, apricots, plus red and yellow peppers. However, a supplement represents a practical way to raise levels quickly and effectively. Synthetic supplements of beta-carotene are well absorbed and utilised by the body, are made to stringent quality standards and are highly concentrated (making tablets small). But there is also evidence that natural beta-carotene provides other possibly more effective chemical forms of the nutrient, and that bioavailability may be improved by the presence of other complementary carotenoids. On the downside, it is difficult and expensive to get high doses of natural beta-carotene in a small tablet.

Vitamin B12 is found in foods such as meat, fish, dairy produce, brewer’s yeast and fermented Soya bean products. As a nutrient, vitamin B12 can be synthesised by bacteria in a fermentation process (see How Vitamins Are Synthesised), or it may be supplied by algae-type supplements such as spirulina and chiorella. Synthesised forms of this vitamin can be made into high dose tablets. Algal forms of vitamin B12 are more synergistic, but usually lower in strength than in synthetic supplements.

Vitamin E is found in wheat germ oil, avocados, nuts and seeds. Natural source vitamin E (d-alpha tocopherol) alpha tocopherol), and to ensure consistency between products the labelling regulations require that the potency of vitamin E stated on the label always refers to the d-alpha tocophero equivalent. However, current labelling rules only account for a 36% potency difference between d- and dl-alpha tocopherol and recent studies indicate natural vitamin E may actually be twice as effective.


The precise details of how many vitamins are synthesised is a closed trade secret. However, in a number of cases, it is via an enzyme-assisted bacterial fermentation process. Unlike humans, bacteria make their own vitamins, and - to put the process simply - by growing bacteria on a substrate that is missing the vitamin you want, you can get the bug to produce it for you. Other vitamins are produced chemically, via a set of reactions from a starter ingredient which itself may be extracted from a food.

Minerals are inorganic substances and therefore cannot be manufactured. They are part of the earth’s crust, and we obtain them in our diets either from plants that have assimilated minerals from the soil (e.g. calcium in spinach), or from eating the animals that have consumed the plants (e.g. iron in liver).

Supplements provide minerals that have ultimately come directly from the ground. But to facilitate their absorption, these inorganic minerals may be bound to organic matter, e.g., yeast or amino acids.

Human Nutrition and Dietetics, Garrow and James. (9th Edition, 1993, Churchill Livingstone
The International Journal of Alternative and Complementary Medicine, Jan. 1999, Page 20-21.


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