Wednesday, October 01, 2014

Does the Cyanocobalamin form of vitamin B-12 have toxic levels of cyanide?

All plants produce cyanide as a by-product of ethylene synthesis. Some plants naturally contain small amounts of cyanide compounds, including stone fruits (almonds, apples, cherries, peaches, and apricots) as well as lima beans, flax seeds, barley, sorghum, white clover, cassava (tapioca), and bamboo shoots.

The amount of cyanide (2% of the weight, or 20 micrograms cyanide in a 1 mg cyanocobalamin tab) is far less than ingested in many natural foods. Following absorption, vitamin B-12 from whatever source is transformed to either methylcobalamin or 5’-deoxyadenosylcobalamin (dibencoszide). Dibencozide is the predominant form of vitamin B-12 in human tissues (up to 70%).

The human body can detoxify a small amount of cyanide in the liver through the thiosulfate (sulfation) pathway. Poisoning occurs when there is not enough thiosulfate to neutralize all the cyanide present. When you’re talking about a dangerous dose of cyanide, it generally means between 50 and 200 milligrams of hydrogen cyanide… but a 1000 microgram (1 mg) pill of the vitamin B-12 supplement cyanocobalamin contains only 20 micrograms of cyanide, and according to dietitian Jack Norris, “the amount of cyanide in cyanocobalamin is considered to be physiologically insignificant.” That’s 20 micrograms, versus milligrams. There are 1000 micrograms in a milligram, which puts the amount of cyanide in a typical B12 supplement far below toxic levels.

Neither the U.S. National Institutes of Health’s Institute of Medicine (IOM) nor the European Food Safety Agency (EFSA) have set a Tolerable Upper Intake (UL) level of Vitamin B-12 since each agency has concluded that it is not possible to derive an Upper Level because no clearly defined adverse effect could be identified from medical reports.

• The IOM reported, “The IOM did not establish a UL for vitamin B-12 because of its low potential for toxicity. In Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline, the IOM states that "no adverse effects have been associated with excess vitamin B-12 intake from food and supplements in healthy individuals". Findings from intervention trials support these conclusions.”
• The EFSA reported, “There are also no adverse effects known for vitamin B12 from foods, or from supplements in amounts far in excess of needs.”

Therefore, cyanocobalamin, the predominate form of supplemental vitamin B-12, has been deemed non-toxic even at high levels of intake and the presence of small amounts of cyanide is not unusual in foods.

• Centers for Disease Control and Prevention
• Canadian Food Inspection Agency
• EFSA,0.pdf

Wednesday, July 16, 2014

Does Borage Seed Oil contain PAs (Pyrrolizidine Alkaloids)?

Borage Oil does NOT contain detectable levels of PAs (Pyrrolizidine Alkaloids), because they are not co-extracted from the seed along with the oil. In the definitive study "Pyrrolizidine Alkaloid Content in Crude and Processed Borage Oil from Different Processing Stages" published in the highly reputable Journal of the American Oil Chemists Society [JAOCS, Vol. 80, no. 10 (2003)] it was stated:

"The pyrrolizidine alkaloid content of crude borage oil and borage oil from different processing stages was determined by GC-MS. The results showed that no pyrrolizidine alkaloids were present above a detection limit of 20 ppb. The reduction factors for pyrrolizidine alkaloids at various stages in the oil refining process were determined by means of spiking experiments using the commercially available pyrrolizidine alkaloid crotaline. It was shown that the pyrrolizidine content in crude borage oil was reduced overall by a factor of about 30,000 in the refining process."

Based on the scientific evidence, since manufacturers use refined borage seed oil their Borage Oil products would never be expected to contain any measurable PAs (at the current 20 parts-per-billion detection level).

Monday, June 23, 2014

John Oliver's take on "Unregulated" Dietary Supplements

Another salvo in the War on Vitamins and Dietary Supplements:

John Oliver was funny, but not remotely fair or accurate. Some of the more grievous false examples (in my opinion):

• He assumed no new laws or regulations have been implemented since DSHEA (the Dietary Supplement Health & Education Act of 1994)
o Untrue, and some have been championed by industry; some examples:
 The 2002 Anti-Bioterrorism law's food safety regulations
 The implementation of mandatory Good Manufacturing Practices regulations and increasing numbers of FDA audits over the past 4 years
 Bans on steroids and their precursors
 A mandatory Adverse Event Reporting law
 The more recent Food Safety Law

• He showed old news reports speculating that the botanical ephedra killed 155 people, asserting that these deaths occurred because of DSHEA tying FDA’s hands
o FDA was admittedly unable to substantiate any deaths
o FDA was able to ban ephedra under DSHEA anyway based on a solely theoretical one death per year from billions of doses taken, despite two FDA expert panels unable to validate any deaths

• He claimed that FDA and FTC are powerless to act because of DSHEA, Hatch and Harkin
o The number of enforcements have been rapidly increasing
 Warning letters, recalls, even seizures
o The number of FDA inspections has been rapidly increasing

• He showed how many citizens supported DSHEA in 1993-1994, but asserted that they were misled by industry champions Senators Hatch and Harkin, who received donations from the then relatively tiny $2 billion industry
o He implied that Hatch and Harkin did it solely for the money
o He implied that Hatch and Harkin still block all regulation; see above for contrary examples
 some of the more recent laws were supported by industry and even sponsored by Hatch and/or Harkin)

• He assumed that dietary supplements are largely unregulated because of not enough regulation, rather than their relatively good safety record versus drugs or even other foods
o He promoted pre-market approval of products and claims, similar to a failed Canadian strategy that cut product selection without enhancing safety
o He cited DNA testing of botanicals failing 1/3 of products tested, without mentioning that this is actually a proposed but not yet validated assay technology disputed by herbal authorities as far too premature to use as a standard

This does not address his criticisms of Dr. Oz, who can defend himself.

Link to show:

Monday, June 16, 2014

Prebiotics (fiber) may improve metabolic factors in obese people

This is not new to me, but another study confirms that low levels of bifidobacteria are associated with obesity. This has been shown for newborns as well as adults. Consuming prebiotic fiber, i.e. inulin or FOS, can promote the growth of bifidobacteria that reduce the likelihood of obesity and its resulting symptoms/risks.

Obesity may have a microbial component. Adding prebiotic fiber plus bifidobacteria may shift metabolism toward a leaner, healthier equilibrium.

Wednesday, February 12, 2014

Facts About Xylitol

Because of recent confusion and mis-statements by some bloggers, I'd like to report some facts about the sugar alcohol, Xylitol:

Like all sugar alcohols, unabsorbed (versus undigested) material is hygroscopic (attracts water) as it passes through the GI tract. This makes them potentially laxative at various doses; as always, moderation is the key.
o For xylitol, the common threshold is at 30-50 grams a day (1-2 ounces).
o For erythritol, an alternative sugar alcohol, there is practically no laxative effect since it is predominantly absorbed.

Xylitol is naturally found in plums, raspberries, and cauliflower; it is a naturally occurring sweetener that the body can handle.

Xylitol can be made from xylan; a fiber found in many plants including:
o corn husks, cobs, and stalks (corn bobs are the leading commercial source)
o certain hardwoods like birch and beech (relatively small commercial production is done in Europe for Scandinavian trees)
o rice, oat, wheat and cotton seed hulls (possible, but not a typical commercial source)
o various nut shells (possible, but not a typical commercial source)
o straw (possible, but not a typical commercial source)
o sugar cane (possible, but not a typical commercial source)

Xylitol does not require insulin.

Xylitol improves bone and tooth density, protects tooth enamel.

Xylitol has fewer calories than sugar; only about 2.4 calories per gram versus 4 for sugar.

Most xylitol is produced in China.
o However, GMO corn is not allowed for food production in China.
o There are some IP (documented as from non-GMO corn) supplies and others tested as non-GMO (the corn sources are tested before production, though IP is not in place yet).
o GMOs have not been found in xylitol from corn, despite unsubstantiated speculation from bloggers.
o China’s food safety laws have been expanded dramatically in recent years, and in some cases now exceed US standards.

Xylitol can be toxic to dogs, but so is chocolate. Pets can’t always eat our foods, but that doesn’t imply that these foods are somehow harmful to humans. This is a “straw man” argument that fades upon examination.

Monday, January 06, 2014

Most vitamin studies are flawed by poor methodology

In a new published analysis, researchers at the Linus Pauling Institute of Oregon State University report that many large clinical trials of vitamin supplements, especially antioxidants like vitamin C, have flawed methodologies that make them 'useless' in determining the real value of such nutrients.

It is on the basis of such flawed studies created by researchers that are uninformed as to the nature of nutrients that their studies may conclude that vitamins are of no value or may even be harmful.

Of course, common sense tells us that essential nutrients cannot be inherently useless or harmful in reasonable doses, but those are messages that we repeatedly hear in the media reports.  Such flawed science leads to the equally flawed calls for vitamins to be regulated as drugs, adding a new logical error in failing to consider the vast difference in safety between nutrients and drugs.

Drugs are typically synthetic, isolated substances that are foreign to the body and don't act like nutrients, and it is this foreignness of drug properties that make them inherently toxic to the body. That toxicity is the legal basis of regulating drugs as controlled substances, and the failure to demonstrate toxicity of nutrients, except in studies with such flawed methodogies as we are discussing, makes calls to regulate vitamins as drugs hollow and illogical.

A report on that article:

The original peer-reviewed publication in a peer-reviewed nutrition journal: