42 votes
Accepted

Can vitamin B17 cure cancer?

Laetrile/Amygdalin has been claimed to be a suitable treatment for 'cancer' (which is a summary term for an extremely heterogeneous class of diseases). Even though laetrile/amygdalin in these claims ...
AlexDeLarge's user avatar
  • 2,868
42 votes
Accepted

Did neanderthals need vitamin C from the diet?

Humans can't synthesize vitamin C due to a dysfunctional enzyme L-gulonolactone oxidase, or "GULO". From Wikipedia: Loss of GULO activity in the primate order occurred about 63 million ...
Bryan Krause's user avatar
  • 45.6k
21 votes
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Is cancer caused by vitamin B17 deficiency?

Short Answer: No. Background: First of all, there is no such thing as vitamin B17. The compound, amygdalin or laetrile, which is referred to by this term, is not a vitamin1. Amygdalin is indeed a ...
another 'Homo sapien''s user avatar
14 votes

Is cancer caused by vitamin B17 deficiency?

Short version: This is nonsense, cancer does not arise from nutritional deficiencies. Long version: The substance is called Amygdalin, a poisonous cyanogenic glycoside. It can be found in higher ...
Chris's user avatar
  • 51.6k
11 votes
Accepted

How is vitamin B12 stored in the body although it is water-soluble?

Vitamin B12 (cobalamin) is a cofactor required by the enzymes methionine synthase (MTR) and methylmalonyl-CoA mutase (MUT). These are the only known enzymes that use B12 in humans, and are abundant in ...
Roland's user avatar
  • 5,705
6 votes

How is vitamin B12 stored in the body although it is water-soluble?

B12 is stored as mitochondrial 5-deoxyadenosylcobalamin, primarily in the liver (2 to 5 mg) but also about another 1/3rd in muscle. It's estimated that 0.1% of reserves are turned over per day, and ...
jzx's user avatar
  • 1,788
6 votes
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Is it possible that there are unknown vitamins?

Yes, it is possible that there is a vitamin or other essential nutrient that has not been identified so far. Essential nutrient means any substance normally consumed as a constituent of food which is ...
Jan's user avatar
  • 8,079
5 votes

What's unique for vitamin B-12 group?

The common scientific belief around 1900 was that the only dietary components needed to support life were protein, fats, carbohydrates, and salts.[1] In 1912 Hopkins reported on experiments showing ...
mgkrebbs's user avatar
  • 9,054
5 votes
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How is a substance classified as a vitamin?

1) Vitamin D is a bit of an umbrella term that actually refers to a whole group of related molecules. One of these, vitamin D$_3$ (cholecalciferol) is formed spontaneously from ergosterol in the ...
Roland's user avatar
  • 5,705
5 votes

What vitamins exist for other animals but not humans?

The best example I can think of is taurine, which is a non-proteinogenic amino acid. Taurine is "conditionally essential" for humans1, but essential for cats2,3. References: 1: Stapleton, P. P., ...
tyersome's user avatar
  • 5,598
4 votes
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Effect of heat-treatment of Vitamin C

Disclaimer: the denaturation is the process of protein unfolding from their native state. Since vitamin C is not a protein, it cannot denaturate. I think that the word you're looking for is simply "...
LinuxBlanket's user avatar
  • 1,313
4 votes

Vitamins — how did they get their names?

They were more or less named in the order that they were found. Letters F-J are skipped because many of those were reclassified or later found not to be vitamins. The K comes from the German word ...
wanderweeer's user avatar
  • 2,733
4 votes

What's unique for vitamin B-12 group?

According to PeaceHealth: The vitamin B-complex refers to all of the known essential water-soluble vitamins except for vitamin C. Vitamin B was once thought to be a single nutrient. ...
Jan's user avatar
  • 8,079
4 votes

What vitamins exist for other animals but not humans?

Historically, the vitamin concept arose out of nutritional studies that demonstrated the dietary requirements of additional factors not supplied by a diet of protein, carbohydrate and fats. These ...
user338907's user avatar
  • 4,723
3 votes
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Do vitamin enriched foods preserve their value when exposed to higher temperatures?

Here's one estimation about how much vitamins or minerals can get lost due to various "food processing" (cooking, drying, freezing) methods: According to NutritionData, cooking can result in a loss ...
Jan's user avatar
  • 8,079
3 votes

Is vitamin D a vitamin or a hormone?

There's an open access article "From vitamin D to hormone D", which explains the difference(s). Vitamin D is a family of substances, but for humans the most important one from this family is ...
the gods from engineering's user avatar
3 votes

Is there enough vitamin B12 in lakes, rivers and ponds, for humans not to need to take supplements?

Of course there is no evidence for the superiority of the vegan diet claim to begin with, so there is that, and there are plenty of vegan foods fortified with B12, even some from non-animal sources. ...
John's user avatar
  • 14.7k
3 votes

How is a substance classified as a vitamin?

Please keep reading the Wikipedia article, it clarifies substantially in the next several lines, for example (emphasis mine): An organic chemical compound (or related set of compounds) is called a ...
Bryan Krause's user avatar
  • 45.6k
3 votes
Accepted

Where in the biological realm is vitamin B5 chiefly produced?

General Considerations Pantothenic acid is a precursor for the synthesis of Coenzyme A which is essential for most, if not all, living organisms. As bacteria appeared on earth before plants, and can ...
David's user avatar
  • 25.7k
2 votes
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How does vitamin A deficiency arise?

The WHO report "Global prevalence of vitamin A deficiency in populations at risk 1995–2005" (page 12 of 68) puts it like this: Where animal source or fortified foods are minimally consumed, ...
Michael Paul's user avatar
2 votes

Use of sunlight in biological processes

We don't get it from the sun, it's synthesized. Humans can get it... via nutrition. via synthesis in the skin, which depends on UV radiation. Sun is the major source of it (the radiation, not the ...
setempler's user avatar
  • 174
2 votes
Accepted

Why do Arctic predators accumulate vitamin A?

The phytoplankton at the bottom of the food chain have high levels of vitamin A and precursors like beta-carotene. At each step up the chain, vitamin A bioaccumulates. Top predators in the Arctic ...
Draco Freon's user avatar
2 votes

Does vitamin C decrease after reacting with oxygen free radicals?

Correct, vitamin C (ascorbate) acts by donating 1 electron to a free radical (reducing them to a stable compound with paired electrons), and is thereby itself oxidized to semidehydroascorbate. This is ...
Roland's user avatar
  • 5,705
2 votes
Accepted

Nutrition mineral intake method

To absorb essential elements, body must get them in form of stable ions. So for calcium and magnesium, our body absorbs them from the hard water in the same way it obtains from other sources and uses ...
Dax Buddhdev's user avatar
2 votes
Accepted

Is the serum concentration of calcitriol different at different times in the day?

Calcitriol, or 1,25-dihydroxyvitamin D, is produced in the kidney by 25-hydroxyvitamin D-1α-hydroxylase from it's precursor, 25-hydroxyvitamin D. Calcitriol has a plasma half life of about 6 hours. ...
De Novo's user avatar
  • 8,791
2 votes
Accepted

How does the inability to produce vitamin C helped weight gain?

The effect comes indirectly since lower levels of ascorbate increases urate levels, according to Arthritis Rheum. 2005 Jun;52(6):1843-7. The effects of vitamin C supplementation on serum ...
David Jonsson's user avatar
2 votes
Accepted

What does the number after Vitamin B signify?

It appears to be fairly arbitrary, but they were originally numbered chronologically by discovery. However... From Gizmodo: These Bs are not necessarily designated in chronological order, as B12 (...
theforestecologist's user avatar
2 votes

Vitamins — how did they get their names?

1 * Vitamin A: Name: Retinol. It was discovered in 1909 Function: Carotene compound responsible for transferring light to the retina. The most common sources: whale liver oil, meat, eggs, liver, ...
Asma MENAI's user avatar
2 votes
Accepted

What happens to intrinsic factor exactly at the terminal ileum, where B12 is absorbed?

After reversible attachment of intrinsic factor-cobalamin complex to its ileal surface receptor, an energy-dependent process prevents removal of the complex from the cell surface by EDTA or acid; ...
Ojasvi's user avatar
  • 846

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