The seed for Wide00014 was: 
 
 - Slash pages from every domain on the web: 
 
 
 
 
 
 -- a ranking of all URLs that have more than one incoming inter-domain link (rank was determined by number of incoming links using Wide00012 inter domain links) 
 
 
 
 -- up to a maximum of 100 most highly ranked URLs per domain 
 
 - Top ranked pages (up to a max of 100) from every linked-to domain using the Wide00012 inter-domain navigational link graph ||||| Too much vitamin B12 may promote acne, according to a new study. 
 
 The study found that, in the presence of vitamin B12, the skin bacteria that are commonly linked to acne start pumping out inflammatory molecules known to promote pimples. 
 
 In the study, scientists investigated the differences between skin bacteria from people prone to acne and bacteria from people with clear-skinned faces. The researchers looked at the bacteria's gene expression, hoping to figure out why Propionibacterium acnes, which is the most common skin microbe, causes pimples in some people but not in others. 
 
 They found that vitamin B12 changed the gene expression of the skin bacteria, which could have led to acne-promoting inflammation. 
 
 In humans, vitamin B12 plays roles in metabolism, red blood cell formation and the maintenance of the central nervous system. It's commonly found in multivitamins, but the new research could raise questions about whether people with acne should take vitamin B12 supplements. 
 
 "I think there's a link" between vitamin B12 and acne, said Huiying Li, a co-author of the new study and an assistant professor of pharmacology at UCLA's David Geffen School of Medicine. Her team found a molecular pathway that could explain the link in their study, but it will need to be confirmed by future research."There's still a lot to be studied in order to really understand if B12 causes acne," she said. 
 
 Looking for a mechanism 
 
 By looking at the gene expression patterns, Li's team first found that the pathway that produces vitamin B12 was significantly altered in the skin bacteria of people with acne, compared with the skin bacteria of people without acne. This finding raised Li's suspicions about B12's role in acne, she said. Prior studies citing an association between these two elements confirmed the possibility of a link — research dating back to the 1950s has suggested that vitamin B12 supplements could contribute to some people's acne. 
 
 Li's research team then looked at the skin bacterium in pimple-free people who received a vitamin B12 injection. The researchers confirmed that the B12 supplement repressed the expression of genes in P. acnes involved in synthesizing the vitamin. In fact, the expression of those genes was lowered to levels similar to those of acne patients. [4 Common Skin Woes, and How to Fix Them] 
 
 A week after receiving the vitamin B12 injection, one of the 10 participants broke out in pimples. That person's P. acnes gene-expression pattern also changed, the researchers found. Before the B12 injection, it was similar to those of the other healthy participants, but 14 days after the vitamin B12 shot, it looked much more like an acne patient's pattern. 
 
 The researchers also did experiments on P. acnes growing in lab dishes.They found that when they added vitamin B12 to the bacteria, the microbes started producing compounds called porphyrins, which promote inflammation in acne. Inflammation is a key step in the later stages of acne development, Li said. 
 
 Together, the new findings suggest that when too much B12 is present, the bacteria have changes in their gene expression that suppress further synthesis of the vitamin. These bacteria switch to producing porphyrins, the researchers explained, and in some people, this uptick in inflammatory compounds may contribute to acne. 
 
 "We think the pathway we studied could potentially explain part of acne's pathogenesis," Li said. 
 
 Hang on to those vitamins 
 
 But although the study found a possible link, it did not prove that too much vitamin B12 definitely causes or worsens acne. 
 
 "The data and hypothesis are very intriguing, but much additional investigation is required to determine if this is a real cause-and-effect phenomenon," said Josh Miller, a professor of nutritional sciences at Rutgers University who was not involved with the study. 
 
 In addition, although the new findings suggest that B12 supplements may promote inflammation, other studies have suggested the opposite — that vitamin B12 has anti-inflammatory properties, Miller said. 
 
 "Proof of a causative effect of B12 supplements on acne development will require randomized control trials with enough subjects to see a significant effect, if one exists," he told Live Science. 
 
 Li also cautioned that it's way too early to suggest that people dealing with acne should stop taking multivitamins with B12. Most of the studies that have found an increase in acne with vitamin B12 involved large doses of the vitamin, given by injections, she pointed out. 
 
 "This study does present some compelling evidence suggesting that supplementation with B12 can cause or exacerbate acne in a subset of individuals," said Dr. Whitney Bowe, clinical assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai Medical Center in New York. "However, we don't have enough evidence at this point to broadly recommend that all acne patients try to avoid vitamin B12 supplements or foods rich in vitamin B12." 
 
 Beyond zits 
 
 The aim of the research was to better understand how humans, and the microbes that live on their bodies, interact to cause disease, Li said. A deeper understanding of microbial-disease pathways could lead to more targeted treatments, the researchers wrote in their study, published today (June 24) in the journal Science Translational Medicine. 
 
 "The study shows that "what we eat or drink can impact the health of our skin by affecting the microbes that live on our skin," Bowe said. "We have 10 bacterial cells for every one human cell in our body. The more we learn about these bacteria, the more we are realizing the major impact they have on our health and well-being." 
 
 Follow Jennifer Abbasi on Twitter. Follow us @livescience, Facebook & Google+. Original article on Live Science. ||||| A vitamin found in meats and dairy products may be linked to acne, a study published today in Science Translational Medicine suggests. Vitamin B12 alters how the genes of facial bacteria behave — a change that in turn promotes inflammation, which has been linked to pimples in the past. The finding could eventually help create new drugs that can keep acne away. But it’s still very early, so the researchers warn against making any drastic changes to your diet or habits for now. 
 
 "It has been reported several times that people who take B12 develop acne." 
 
 People sometimes take B12 as a supplement to improve memory or combat anemia. But "it has been reported several times that people who take B12 develop acne," says Huiying Li, a molecular pharmacologist at the University of California-Los Angeles and a co-author of the study. "So it’s exciting that we found that the potential link between B12 and acne is through the skin bacteria." 
 
 More than 80 percent of teenagers and young adults have to deal with acne, often on a regular basis. It can go away on its own, but it can also lead to some pretty bad scarring — not to mention some big dips in self-esteem. Unfortunately, researchers don’t know nearly as much about this particular skin condition as one might expect. Scientists have shown that the production of sebum — the oily, waxy stuff your skin makes — and a disorder of the cells that line the inside of hair follicles are both involved in acne development, but the role of bacteria in those pimples we all dread still holds some mysteries. 
 
 That's why Li and her team of researchers decided to look into B12. Since the 1950s, a number of studies have linked the vitamin to acne, but that association was largely anecdotal, Li says. And the researchers had suspected that the vitamin might have an effect on skin bacteria, most notably Propionibacterium acnes. Now, Li and her team think they may have figured out how B12 acts on P. acnes, thanks to experiments her team performed on bacteria taken from a small number of people. 
 
 The study revealed that humans taking B12 end up with high levels of the vitamin in their skin. As a result, P. acnes senses these higher levels and lowers its own production of B12, which it uses to carry out its everyday bacteria-like activities. This causes an imbalance that prompts P. acnes to produce more porphyrins, a related molecule. And unfortunately porphyrins are linked to inflammation — a pretty important factor in the development of severe acne. 
 
 "The main message is that skin bacteria are important." 
 
 Thus, it seems likely that for some people, taking B12 causes inflammation in the skin, which leads to acne. That last step in this pimply chain of events has yet to be demonstrated, however. Doing so will take a bit more time, Li says. 
 
 "The main message is that skin bacteria are important," Li says. They're contributing members of our skin's society, and they like to do things in a certain manner. But until other researchers confirm the link between B12 and acne in a larger number of people, dermatologists won’t really be able to make any clinical recommendations one way or the other, she says. Still, just knowing about the ways in which we can affect the organisms that live on our skin is pretty fun. "I don't want people to misinterpret the results by not taking B12," Li says — this is all about the bacteria. ||||| It is an essential nutrient that helps the brain, nerves and blood work properly and which is found in meat, fish, eggs, dairy products and Marmite. 
 
 But it turns out that vitamin B12 could be causing acne, the skin disorder that results in spots, pimples and blackheads, scientists have found. 
 
 A new study has found that the vitamin changes the way bacteria behave on the skin of susceptible people. 
 
 Vegan diets could be the key to getting rid of spots, because B12 is mostly found in animal products. But be warned: not getting enough of the vitamin can lead to fatigue and a lack of energy. 
 
 The discovery could lead to new treatments for the distressing skin disorder, and shed light on why some people who take vitamin B12 supplements come out in spots. 
 
 While it was already known that taking the vitamin pills can result in acne flare-ups, no-one knew exactly why. 
 
 The new study solved the mystery by showing that the vitamin alters the metabolic activity of the skin bug responsible for acne, Propionibacterium acnes. 
 
 This causes the bacteria to secrete an inflammatory compound that in turn triggers pimples. 
 
 But the effect is not the same for everyone - some people are more vulnerable than others due to the complex interaction of bacteria and host. 
 
 Researchers led by Dr Huiyang Li, from the University of California, Los Angeles, write in the journal Science Translational Medicine: "Our findings suggest a new bacterial pathogenesis pathway in acne and provide one molecular explanation for the long-standing clinical observation that vitamin B12 supplementation leads to acne development in a subset of individuals. 
 
 The paper adds that “interactions between the host and the skin … play essential roles in disease development”. 
 
 The research involved testing 10 volunteers who were all given vitamin B12 supplements. Within a week, just one of them broke out in spots. 
 
 To investigate what had happened the researchers collected bacterial samples from the participants' noses using deep-cleansing pore strips. 
 
 They discovered that excess B12 quenched the bacteria's own production of the vitamin, which had the effect of boosting levels of an inflammatory compound, porphyrin, released by the bugs. Porphyrin is known to drive the inflammatory skin response linked to acne. 
 
 Read more Vitamin B12 may protect brain, says report 
 
 The researchers added: "Future follow-up studies may potentially lead to the development of new therapeutics for this medically important disease." 
 
 The study proves the link between B12 and skin bacteria - but that doesn't mean people should stop taking B12, the researchers stress. 
 
 Vitamin B12 plays key roles in the normal functioning of the brain and nervous system, and red blood cell formation. Deficiency of the vitamin can lead to fatigue and lack of energy. 
 
 Perhaps the solution is to adopt a strict vegan diet – just make sure you avoid a certain divisive spread made out of yeast extract. 
 
 Additional reporting by Press Association
– Nature giveth, and nature taketh away. The same vitamin credited with helping the brain and nervous system—B12—is now accused of contributing to acne, reports the Independent. A new UCLA study suggests a link, though researchers emphasized that more research needs to be done to confirm what's actually happening. Still, the findings "could raise questions about whether people with acne should take vitamin B12 supplements," observes Live Science. It seems that the vitamin changes the way skin bacteria behaves, which promotes inflammation, which in turn leads to pimples. Some people are more vulnerable than others. "This study does present some compelling evidence suggesting that supplementation with B12 can cause or exacerbate acne in a subset of individuals," says a co-author of the study. She emphasizes that the research shows correlation, not causation. While previous studies have linked the vitamin to acne flareups, this is the first to provide details on how it interacts on a molecular level with bacteria, especially Propionibacterium acnes. One upside of the research is that it might eventually lead to better acne medication, reports the Verge. (Kids may be getting too many vitamins in cereal.)