By: Robert J Thiel, Ph.D., N.D.
Introduction
At our office, we sometimes recommend products which contain various B vitamins. Some of our clients have indicated that the synthetic B vitamins that they take are at least as good because they normally contain higher amounts of the individual vitamins than the food formulas we normally recommend. Is this true? Are humans better off eating higher amounts of un-natural synthetics or smaller amounts of food complex B vitamins?
United States Pharmacopoeia (USP) synthetic vitamin B isolates are not food, even though they are often called “natural” and are sometimes added to foods—they are synthesized, standardized chemical isolates1. In nature, vitamins are never isolated: they are always present in the form of food vitamin-complexes2-4. This paper will discuss some of the physiochemical differences between individual natural B vitamins and synthetic ones, as well as cite clinical research which suggest that vitamins in a food complex are superior to USP isolated ones.
Vitamin B1, Thiamin The free vitamin B1 (called thiamin) is a base. When it is synthesized it becomes a solid salt such as thiamin hydrochloride or thiamin mononitrate5. Synthetically thiamin is usually marketed as thiamin hydrochloride or thiamin mononitrate6 and is a made from Grewe diamine (a coal tar derivative7) processed with ammonia and other chemicals8. No thiamin hydrochloride (often listed as thiamin HCL) or thiamin mononitrate is naturally found in food or the body (thiamin pyrophosphate is the predominant form in the body(9) 6. Yeast and legumes are excellent food sources of natural thiamin9.
“Thiamin is rapidly destroyed above pH 8…the addition of sodium bicarbonate to green beans and peas to retain their color or to dried beans to soften their skins inactivates thiamin” 9. High heat, x-rays, and UV irradiation also destroy thiamin9,10 Thiamin mononitrate tends to be used for food fortification since it is more stable under storage and processing conditions 6. An animal study found that a natural food complex vitamin B1 was absorbed 1.38 times more into the blood and was retained 1.27 times more in the liver than an isolated USP thiamin hydrochloride11.
Vitamin B2, Riboflavin The free vitamin B2 (called riboflavin) is a weak base. When synthesized it becomes an orange amorphous solid12. Some synthetic riboflavin analogues have very weak vitaminic activity12. Some natural variations, especially in coenzyme forms, occur in plant (including fungal) species13. One study found that the pasteurization of bovine milk seems to reduce the bound form of riboflavin from 13.6% to 2% [14]. An animal study found that a natural food complex vitamin B2 was absorbed into the blood and was retained 1.92 times more in the liver than an isolated USP riboflavin 11.
Vitamin ‘B3’, Niacinamide “Niacin is a generic term…the two coenzymes that are the metabolically active forms of niacin (are)…nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP)…Only small amounts of free forms of niacin occur in nature. Most of the niacin in food is present as a component of NAD and NADP…nicotinamide is more soluble in water, alcohol, and ether than nicotinic acid…many analogues of niacin have been synthesized, some of which have antivitamin activity “15.
Niacinamide (also called nicotinamide) is considered to have less potential side-effects than niacin15; it also does not seem to cause gastrointestinal upset or hepatotoxicity that the synthetic time-released niacin can cause16. Beef, legumes, cereal grains, yeast, and fish are significant natural food sources of vitamin B316. Processing losses for this vitamin are mainly due to water leaching17. Synthetic niacin is usually made in a process involving formaldehyde and ammonia8. An animal study found that natural food complex niacinamide is 3.94 times more absorbed in the blood than USP niacinamide and 1.7 times more retained in the liver than isolated USP niacinamide11.
Vitamin ‘B5’, Pantothenate Pantothenate was once known as vitamin B518. USP “Pantothenic acid consists of pantoic acid in amide linkage to beta-alanine”, but the vitamin sometimes referred to as B-5 is not found that way in nature19. In food it is found as pantothenate; foods do not naturally contain pantothenic acid19. “Synthetic D-pantothenate, the active enantiomer is available as a calcium or sodium salt. However, multivitamin preparations commonly contain its more stable alcohol derivative, panthenol”20. Producing synthetic pantothenic acid involves the use of formaldehyde8. Organ meats, yeast, egg yolks, and broccoli are rich dietary sources of natural pantothenate20. Cooking meat and the processing of vegetables lead to significant losses of pantothenate (15-50% and 37-78% respectively)20.
Vitamin B6 “An understanding of the various forms and quantities of these forms in foods is important in the evaluation of the bioavailability and metabolism of vitamin B-6″… one of the forms that vitamin B-6 exists is in the form of “5’0-(beta-Dglycopyransosyl) pyridoxine. To date only plant foods have been found to contain this interesting form of vitamin B-6”21. Yeast and rice bran contain more natural vitamin B6 than other foods22. The most common form in vitamin pills is USP pyridoxine hydrochloride which is not naturally found in food23. At least one synthetic vitamin B-6 analogue has been found to inhibit natural vitamin B6 action24.
Vitamin B6 supports the nervous, skin, and tongue; severe shortages result in abnormal brain patterns and convulsions25. Synthetic B6 usually requires formaldehyde in its production 49 and the extremely high amounts used in some synthetic supplements poses more risk than the lower amounts generally found in food vitamins 23. An animal study found that natural food complex vitamin B6 was absorbed 2.54 times more into the blood and was retained 1.56 times more in the liver than an isolated USP form11.
Vitamin ‘B9’, Folate The vitamin once known as vitamin M (and also vitamin B918) exists in foods as folate (also known as pteroylglutamate)26. Initially, natural food complex folate was given for people with a pregnancy-related anemia in the form of autolyzed yeast; later a synthetic USP isolate was developed26. Pteroylglutamic acid, the common pharmacological (USP) form known as folic acid, is not found significantly as such in the body and appears to be absorbed differently than folate26. Folic acid is not found in foods, but folate is26. Herbert reports a study found “that consumption of more than 266mcg of synthetic folic acid (PGA) results in absorption of unreduced PGA, which may interfere with folate metabolism for a period of years” 26. Fortification with synthetic folic acid has been found to increase consumption for those who already have higher dietary intakes of folate more than those with lower intakes27. It is believed that fortification with synthetic folic acid may put a portion of the population at risk for vitamin B12 deficiency28, yet all grain products advertised as enriched must (according to the US FDA) be fortified with folic acid29. “Foods with the highest folate content per dry weight include yeast, liver and organ meats, fresh green vegetables and some fruits”26. Food processing is a concern since “50-95% of folate in food may be destroyed by protracted cooking or other processing such as canning, and all folate is lost from refined foods such as sugars, hard liquor, and hard candies”26. An animal study found that a natural food complex folate was absorbed only 1.07 times more into the blood, yet was retained 2.13 times more in the liver than isolated USP folic acid 11.
Vitamin B12 Initially natural food complex vitamin B12 was given for people with pernicious anemia in the form of raw liver, but due to cost considerations a synthetic USP isolate was developed30. Cyanocobalamin (the common pharmacological/USP form of vitamin B12) is not found significantly as such in the body; it is usually present in reduced metabolically active coenzyme forms (without the cyanide) often conjugated in peptide linkage31-32. According to Herbert (and others) vitamin B-12 when ingested in its human-active form is non-toxic, yet Herbert and Das have warned that “the efficacy and safety of the vitamin B12 analogues created by nutrient-nutrient interaction in vitamin-mineral supplements is unknown”31. Some synthetic vitamin B12 analogues seem to be antagonistic to vitamin B12 activity in the body 33-34. Synthetic B-12 is made through a fermentation process with the addition of cyanide8. An animal study found that a natural food complex vitamin B12 was absorbed 2.56 times more into the blood and was retained 1.59 times more in the liver than isolated USP cyanocobalamin11.
Food Processing and Fortification
The primary reason that nutrition became recognized as a separate science was the result of food processing. The refining of brown rice into white rice reduced B-complex vitamins and initially led to deaths in Asia due to beriberi5,35. At first beri-beri was thought to be due to an infection, until it was learned that it was due to a lack of B vitamins. Actually, the reason they are called ‘B’ vitamins, is that the B initially stood for ‘beri-beri’. The ‘solution’ to beri-beri was to add synthetic USP vitamins. Even though synthetic USP vitamins are added to white rice and does help prevent beri-beri, this ‘fortified’ white rice does not contain the same nutrients as unpolished brown rice (nor does white flour contain the same nutrients as whole flour)35,36 and can contribute to other health problems (such as constipation due to lack of fiber). Adding synthetics, most of which are not in the same chemical form as found in food vitamins, forces the body to digest them in ways it never should have to—why add this unnatural digestive stress?
The earlier refining of corn meal which reduced natural vitamin B-3 and amino acid levels was so devastating it produced around U.S. 7,000 deaths per year for several decades [37]. The refining of whole grains (including wheat, rice, and corn) has resulted in a dramatic reduction of their natural food complex nutrients25,35. The milling of wheat to white flour reduces the natural food complex vitamin and mineral content by 40-60%35. Various food processing techniques (including pasteurization of milk) reduce the available vitamin B6 in foods by 10-50%35-36. Irradiation of meat and other foods “changes the characteristics of food”6 and has been found to reduce levels of vitamins B1, B6, and other nutrient levels6,22,37. Unknown nutrients may also be affected from food processing. No one yet knows how the combinations of these more recent food processing techniques will effect human health38, but it is not likely that they will promote optimal nutrition. In nature, vitamins are never isolated. The primary reason that isolated USP vitamins were developed was cost30.
A secondary reason probably was standardization (it is harder to standardize food), including stability1,6,26. Neither reason justifies placing USP isolates on the same health level as natural vitamins as found in foods.
Conclusion
Studies suggest that the bioavailability of natural food complex B vitamins is better than that of isolated USP vitaminse.g. 5,12, that they may have better effects on maintaining aspects of human health beyond traditional vitamin deficiency syndromes, and at least some seem to be preferentially retained by the human body11. It is not always clear if these advantages are due to the physiochemical form of the vitamin, with the other food constituents that are naturally found with them, or some combination.
Regardless, it seems logical to conclude that for purposes of maintaining normal health, natural vitamins are superior to synthetic ones. Eating high dose synthetic B vitamins is like trying to make a computer when you only have 90% of the pieces with many of those pieces being larger than normal size; eating natural B vitamins is like trying to make a computer with 100% of the parts with all the parts the correct size. Which of the ‘computers’ would work better? Obviously the one with 100% of the right parts!
Most people can improve their health by eating health-building whole foods such as fruits and vegetables and whole grains (and consuming less refined carbohydrates) [25]. This alone can help increase the consumption of natural B vitamins. Vitamin B nutrition should come from food or from supplements which are as close to food as possible. Since no one knows everything there is to know about nutrition, it seems logical from both a historical and modern perspective to consume vitamins in the forms found in natural food complexes and not to try to build health based on chemical isolates.
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