字幕英文翻譯 English translation of the video transcript ⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇ If you were to ask me which vitamin I find the most complex, I would, without hesitation, tell you it’s vitamin B12. Let’s explore why. First of all, a single molecule of B12 undergoes a highly intricate journey from dietary intake to being absorbed into cells. This process requires various bodily conditions and specific proteins to facilitate its path. If even one step of this chain malfunctions, it can lead to a B12 deficiency in the body. Additionally, the B12 molecule is the largest of all vitamins. Not only is it large, but it also has an extraordinarily complex and diverse structure. This complexity results in four naturally occurring forms of B12, each with distinct chemical properties. These variations make B12 metabolism particularly susceptible to issues caused by genetic factors, affecting its usability in the human body. While it’s true that vitamin B12 can be easily obtained from animal-based foods, the increasing prevalence of vegetarianism poses a significant challenge for this group to get adequate B12 intake. But even among those who don’t follow a vegetarian diet, modern dietary habits rely increasingly on processed foods as a primary calorie source. These processed or ultra-processed foods, though convenient and energy-dense, often lack sufficient trace elements, including vitamin B12. So don’t assume that simply paying attention to your diet means you won’t be deficient in B12. Statistics show that up to 20% of the population is deficient in vitamin B12, and the likelihood increases with age. However, the problem doesn’t end there. While dietary deficiencies of B12 can be addressed with supplements, research in recent years has raised concerns about over-supplementation. Studies suggest that long-term consumption of high doses of B12, or blood tests showing excessive B12 concentrations, can significantly increase the risk of certain cancers or mortality rates. Conversely, insufficient dietary B12 intake or low blood B12 levels are also associated with increased mortality. In other words, both excess and deficiency pose risks. This presents a frustrating dilemma: a vitamin deficiency that leads to severe illness is widespread, yet over-supplementation can also harm the body. So, what’s the solution? In this video, I’ll address several important questions, such as the differences among various forms of vitamin B12, their distinct impacts on the body, and how to supplement B12 long-term in a safe and effective way. Finally, I’ll attempt to explain why long-term use of vitamin B12 or high blood concentrations may cause adverse effects, along with the potential scientific reasons behind this. These are critical topics, so be sure to watch until the end! Let’s begin with a brief explanation of how a vitamin B12 molecule journeys from food to body cells. First, it binds with haptocorrin (a type of transcobalamin protein) in the mouth and is carried into the stomach. Haptocorrin, a protein secreted by salivary glands, acts as a protector, shielding B12 from being destroyed by stomach acid. Next, the B12 molecule, escorted by haptocorrin, passes through the acidic environment of the stomach and reaches the duodenum, where it switches to binding with intrinsic factor (IF). The intrinsic factor then delivers B12 to the intestinal lining, where it is absorbed into the bloodstream. Once in the bloodstream, the B12 molecules bind with a different transcobalamin protein (Type II) and are transported to cells needing vitamin B12. The transcobalamin proteins-Type I (haptocorrin), intrinsic factor, and Type II-are the three key proteins involved in B12 transportation. When the Type II protein enters the cell with B12, they separate, allowing B12 to be released. At this stage, cellular enzymes cleave the B12 molecule, detaching its core from the molecular "caps" attached to it. Imagine B12 as a group of individuals wearing four distinct hats. Once the hats are removed, they all look identical, and their differences are defined by the hats (or molecular groups) they wear. These molecular groups come in four types: methyl, cyano, hydroxy, and adenosyl. These represent the four natural forms of B12 found in foods and supplements, each with slightly different physiological properties. When B12’s core is freed by enzymes, cells can reattach different caps based on current physiological needs. For instance, if a cell requires B12 in the cytoplasm, it adds a methyl group, forming methylcobalamin, which serves as a coenzyme for critical cytoplasmic enzymes. Alternatively, if the mitochondria need B12, an adenosyl group is added, forming adenosylcobalamin, which acts as a coenzyme in mitochondrial energy production. In essence, while there are four "hats," only two-methyl and adenosyl-are functionally active in the body as coenzymes. Coenzymes are enzyme assistants, crucial for executing biochemical tasks. For example, vitamin C, another coenzyme, aids collagen-synthesizing enzymes in building and stabilizing collagen structures. Without vitamin C, collagen synthesis is impaired, leading to scurvy, a severe condition characterized by unhealed wounds, loose teeth, and bleeding. Thus, the notion that methylcobalamin is the "best" B12 supplement is not entirely accurate. Regardless of the B12 form consumed, enzymes within cells will remove the molecular group, and the body will reassemble B12 based on its needs. Let’s move on to the next question: do different forms of B12 have distinct physiological effects, and which is best for the body? While all four forms bind strongly to the three transport proteins, there are slight differences in their properties. For example, hydroxocobalamin is better suited for individuals with slower B12 metabolism or certain genetic disorders that hinder the conversion of B12 into its active coenzyme forms. Intravenous hydroxocobalamin can address this issue because it binds more tightly to transport proteins, allowing more time for conversion within cells. Moreover, hydroxocobalamin is quicker to release its hydroxy group, making it more readily usable. Research shows that most B12 in the blood of healthy adults comes from hydroxocobalamin, comprising about 50% of total B12. Hydroxocobalamin is also a treatment for cyanide poisoning, utilizing its ability to rapidly exchange its hydroxy group with cyanide, forming non-toxic cyanocobalamin. Conversely, methylcobalamin is less tightly bound to transport proteins and is more quickly excreted through urine. While it’s an active coenzyme, the belief that it’s inherently superior lacks strong justification. Cyanocobalamin, though less popular, has the advantage of stability, making it ideal for long-term storage in supplements. Its stability compensates for its lesser reactivity compared to hydroxocobalamin. Now, let’s address why excessive B12 intake or high blood levels are associated with health risks. Excess B12 intake has been linked to an increased risk of esophageal cancer, with studies showing a 75% higher risk in those with the highest intake levels compared to the lowest. This risk is even more pronounced in non-drinkers, with nearly a threefold increase. While some hypothesized this risk was due to red meat (a common B12 source), studies have shown it’s not related to dietary sources but to B12 itself. Over-supplementation may disrupt DNA methylation processes, leading to cellular damage and long-term harm. Regarding blood B12 levels, studies consistently show a J-shaped curve for mortality, with optimal levels between 400 and 500 ng/ml. Levels above or below this range are linked to higher death rates due to insufficient or excessive B12’s effects on vital functions like DNA synthesis, nerve health, and red blood cell production. But why can high concentrations of vitamin B12 also be detrimental to health? There are several possible explanations. First, free vitamin B12 in the bloodstream is filtered out by the kidneys. If kidney function is impaired, vitamin B12 levels in the blood can become elevated. In other words, high B12 levels may reflect underlying kidney dysfunction. Similarly, when liver function declines, in cases of certain cancers, or in patients with blood-related diseases such as leukemia, the body tends to produce more transcobalamin proteins. These proteins have a strong affinity for vitamin B12, causing it to remain in the bloodstream for a longer time. Therefore, detecting high levels of vitamin B12 may actually indicate the presence of these underlying chronic conditions. Lastly, excess vitamin B12 is stored in the liver. However, in cases of liver disease where significant liver cell death occurs, the stored vitamin B12 is released from the damaged liver cells, leading to elevated levels in the bloodstream. To summarize, excessively high concentrations of vitamin B12 in the blood are often indicators of underlying liver disease, kidney disease, cancer, or blood disorders. These chronic illnesses inherently have a negative impact on survival rates. In today’s video, I’ve addressed the previously raised questions about vitamin B12, hoping to provide you with a deeper understanding of this essential vitamin. In clinical practice, for nutrients like vitamin B12 and vitamin D-where maintaining blood concentrations within a specific range is crucial-regular blood tests are important to ensure they stay at ideal levels. As for how much to supplement and for how long, this depends on your blood concentration levels. There isn’t a fixed dosage or duration. Regular monitoring of blood levels is the best way to ensure you’re getting the maximum benefits from nutritional supplements. That wraps up today’s video. Thank you all for watching, and I’ll see you in the next episode. Bye-bye!
字幕英文翻譯
English translation of the video transcript
⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇
If you were to ask me which vitamin I find the most complex, I would, without hesitation, tell you it’s vitamin B12.
Let’s explore why.
First of all, a single molecule of B12 undergoes a highly intricate journey from dietary intake to being absorbed into cells. This process requires various bodily conditions and specific proteins to facilitate its path. If even one step of this chain malfunctions, it can lead to a B12 deficiency in the body.
Additionally, the B12 molecule is the largest of all vitamins. Not only is it large, but it also has an extraordinarily complex and diverse structure. This complexity results in four naturally occurring forms of B12, each with distinct chemical properties. These variations make B12 metabolism particularly susceptible to issues caused by genetic factors, affecting its usability in the human body.
While it’s true that vitamin B12 can be easily obtained from animal-based foods, the increasing prevalence of vegetarianism poses a significant challenge for this group to get adequate B12 intake.
But even among those who don’t follow a vegetarian diet, modern dietary habits rely increasingly on processed foods as a primary calorie source. These processed or ultra-processed foods, though convenient and energy-dense, often lack sufficient trace elements, including vitamin B12.
So don’t assume that simply paying attention to your diet means you won’t be deficient in B12. Statistics show that up to 20% of the population is deficient in vitamin B12, and the likelihood increases with age.
However, the problem doesn’t end there. While dietary deficiencies of B12 can be addressed with supplements, research in recent years has raised concerns about over-supplementation. Studies suggest that long-term consumption of high doses of B12, or blood tests showing excessive B12 concentrations, can significantly increase the risk of certain cancers or mortality rates.
Conversely, insufficient dietary B12 intake or low blood B12 levels are also associated with increased mortality. In other words, both excess and deficiency pose risks.
This presents a frustrating dilemma: a vitamin deficiency that leads to severe illness is widespread, yet over-supplementation can also harm the body. So, what’s the solution?
In this video, I’ll address several important questions, such as the differences among various forms of vitamin B12, their distinct impacts on the body, and how to supplement B12 long-term in a safe and effective way.
Finally, I’ll attempt to explain why long-term use of vitamin B12 or high blood concentrations may cause adverse effects, along with the potential scientific reasons behind this.
These are critical topics, so be sure to watch until the end!
Let’s begin with a brief explanation of how a vitamin B12 molecule journeys from food to body cells.
First, it binds with haptocorrin (a type of transcobalamin protein) in the mouth and is carried into the stomach. Haptocorrin, a protein secreted by salivary glands, acts as a protector, shielding B12 from being destroyed by stomach acid.
Next, the B12 molecule, escorted by haptocorrin, passes through the acidic environment of the stomach and reaches the duodenum, where it switches to binding with intrinsic factor (IF). The intrinsic factor then delivers B12 to the intestinal lining, where it is absorbed into the bloodstream.
Once in the bloodstream, the B12 molecules bind with a different transcobalamin protein (Type II) and are transported to cells needing vitamin B12.
The transcobalamin proteins-Type I (haptocorrin), intrinsic factor, and Type II-are the three key proteins involved in B12 transportation. When the Type II protein enters the cell with B12, they separate, allowing B12 to be released.
At this stage, cellular enzymes cleave the B12 molecule, detaching its core from the molecular "caps" attached to it. Imagine B12 as a group of individuals wearing four distinct hats. Once the hats are removed, they all look identical, and their differences are defined by the hats (or molecular groups) they wear.
These molecular groups come in four types: methyl, cyano, hydroxy, and adenosyl. These represent the four natural forms of B12 found in foods and supplements, each with slightly different physiological properties.
When B12’s core is freed by enzymes, cells can reattach different caps based on current physiological needs. For instance, if a cell requires B12 in the cytoplasm, it adds a methyl group, forming methylcobalamin, which serves as a coenzyme for critical cytoplasmic enzymes.
Alternatively, if the mitochondria need B12, an adenosyl group is added, forming adenosylcobalamin, which acts as a coenzyme in mitochondrial energy production.
In essence, while there are four "hats," only two-methyl and adenosyl-are functionally active in the body as coenzymes. Coenzymes are enzyme assistants, crucial for executing biochemical tasks. For example, vitamin C, another coenzyme, aids collagen-synthesizing enzymes in building and stabilizing collagen structures. Without vitamin C, collagen synthesis is impaired, leading to scurvy, a severe condition characterized by unhealed wounds, loose teeth, and bleeding.
Thus, the notion that methylcobalamin is the "best" B12 supplement is not entirely accurate. Regardless of the B12 form consumed, enzymes within cells will remove the molecular group, and the body will reassemble B12 based on its needs.
Let’s move on to the next question: do different forms of B12 have distinct physiological effects, and which is best for the body?
While all four forms bind strongly to the three transport proteins, there are slight differences in their properties. For example, hydroxocobalamin is better suited for individuals with slower B12 metabolism or certain genetic disorders that hinder the conversion of B12 into its active coenzyme forms. Intravenous hydroxocobalamin can address this issue because it binds more tightly to transport proteins, allowing more time for conversion within cells.
Moreover, hydroxocobalamin is quicker to release its hydroxy group, making it more readily usable. Research shows that most B12 in the blood of healthy adults comes from hydroxocobalamin, comprising about 50% of total B12.
Hydroxocobalamin is also a treatment for cyanide poisoning, utilizing its ability to rapidly exchange its hydroxy group with cyanide, forming non-toxic cyanocobalamin.
Conversely, methylcobalamin is less tightly bound to transport proteins and is more quickly excreted through urine. While it’s an active coenzyme, the belief that it’s inherently superior lacks strong justification.
Cyanocobalamin, though less popular, has the advantage of stability, making it ideal for long-term storage in supplements. Its stability compensates for its lesser reactivity compared to hydroxocobalamin.
Now, let’s address why excessive B12 intake or high blood levels are associated with health risks.
Excess B12 intake has been linked to an increased risk of esophageal cancer, with studies showing a 75% higher risk in those with the highest intake levels compared to the lowest. This risk is even more pronounced in non-drinkers, with nearly a threefold increase.
While some hypothesized this risk was due to red meat (a common B12 source), studies have shown it’s not related to dietary sources but to B12 itself. Over-supplementation may disrupt DNA methylation processes, leading to cellular damage and long-term harm.
Regarding blood B12 levels, studies consistently show a J-shaped curve for mortality, with optimal levels between 400 and 500 ng/ml. Levels above or below this range are linked to higher death rates due to insufficient or excessive B12’s effects on vital functions like DNA synthesis, nerve health, and red blood cell production.
But why can high concentrations of vitamin B12 also be detrimental to health? There are several possible explanations.
First, free vitamin B12 in the bloodstream is filtered out by the kidneys. If kidney function is impaired, vitamin B12 levels in the blood can become elevated. In other words, high B12 levels may reflect underlying kidney dysfunction.
Similarly, when liver function declines, in cases of certain cancers, or in patients with blood-related diseases such as leukemia, the body tends to produce more transcobalamin proteins. These proteins have a strong affinity for vitamin B12, causing it to remain in the bloodstream for a longer time. Therefore, detecting high levels of vitamin B12 may actually indicate the presence of these underlying chronic conditions.
Lastly, excess vitamin B12 is stored in the liver. However, in cases of liver disease where significant liver cell death occurs, the stored vitamin B12 is released from the damaged liver cells, leading to elevated levels in the bloodstream.
To summarize, excessively high concentrations of vitamin B12 in the blood are often indicators of underlying liver disease, kidney disease, cancer, or blood disorders. These chronic illnesses inherently have a negative impact on survival rates.
In today’s video, I’ve addressed the previously raised questions about vitamin B12, hoping to provide you with a deeper understanding of this essential vitamin.
In clinical practice, for nutrients like vitamin B12 and vitamin D-where maintaining blood concentrations within a specific range is crucial-regular blood tests are important to ensure they stay at ideal levels.
As for how much to supplement and for how long, this depends on your blood concentration levels. There isn’t a fixed dosage or duration. Regular monitoring of blood levels is the best way to ensure you’re getting the maximum benefits from nutritional supplements.
That wraps up today’s video. Thank you all for watching, and I’ll see you in the next episode. Bye-bye!
Wow a full copy of translation❣️ Good job 👍 Thanks for sharing your professional information 😘
Thank you Dr.Chang🙏
Thanks and appreciated your English version. Very helpful,! You are very kind, caring and professional doctor. 🙏🙏🙏🙏🙏👍👍👍👍👍
感謝張醫師的詳盡說明
11:47 血液中B12的濃度宜維持在450左右，太高或太低，死亡率都會上升
13:16 維他命B12在血液中的濃度過高，代表身體出狀況，可能是肝臟疾病、腎臟疾病、癌症、或血液疾病
13:33 補充B12時，要注意讓血液中濃度控制在400到500之間
13:50 必須定時抽血檢查，以便確保維他命B12的血中濃度正常；維他命D也是如此。
謝謝您的整理🤗
🙏感恩
甲基B12(methylcobalamin)
氰基B12(cyanocobalamin)
氫氧基B12(hydroxylcobalamin)
去氧腺苷B12(adenosylcobalamin)
能夠不斷地學習進步，真的是很棒的醫師，以前的醫師很多都在獲取資格後就從來沒有再進修過了，以至於後面很多醫師給我們的觀念都是錯的，現在資訊發達了，好醫師也更努力的在精進，相信一樣是醫師也會有不一樣的觀點，這樣彼此學習的條件下會是大家的福祉，有聽過方識欽醫師對B12的見解，如果醫師間可以互相整合精進觀點，將會帶給大家健康很大的幫助，謝謝醫師，感謝。
謝謝您的支持🙂🙂😊
感謝醫師用淺顯易懂的方式解說這麼複雜的機制😂 很有收穫！❤
您說淺顯易懂真是讓我太感動了😄
张医师，能不能说明一下缺乏b12有什么症状？什么样的人需要补充b12
雖然有一點複雜但醫師講的還蠻清楚的。謝謝醫師。
看到柴柴了❤
感謝您的收看😍
重點在血中濃度，若有異常，必須儘早檢查其他器官的功能
是的👍👍
張醫師講解非常專業，一定花了不少時間準備！喜歡柴總❤
大部分的腳本是在歐洲的旅途上寫出來的😵💫😆
太敬業啦！感恩❤🙏
我一發現張醫生的好影片,馬上點讚訂閱.(終於不用被"網路傳說"欺騙.) 關於B群家族. 請問 B1=thiamin HCl, B2=Riboflavin-5-Phosphate, B3=Inositol hexaniacinate, B5=calcium pantothenate, B6=pyridoxine HCl, B9= Metafolin, L-5-MTHF, 可以分析一下這些B # 的形式, 各有什麼益/壞處嗎? 謝謝
有柴柴，按讚🎉🎉🎉
柴柴😉今天比較愛睏
這集長知識了👍👍👍👍👍
感謝您的收看😄
說明很詳細，謝謝你
感謝您的收看😇
非常感謝張醫師專業詳細分析。 我最近一個月口腔牙肉、舌頭和嘴唇都會腫脹痛，舌頭刮損，我吞咽和說話困難。令到我非常困擾和擔心身體出現什麼問題。我剛做了維生素B 12血液測試。我的濃度超標，Conv. Unit：3982pg/ml. Ref. Range: 187-883. S.I. Unit:2938 pool/L. Ref. Range: 138-652. 請問我這樣的指數是否影響我口腔舌頭牙齦牙肉和嘴唇腫脹痛的問題？ 或我應在做什麼檢查? 請問可如何減低我身體內維生素B 12的濃度？ 期待你的答覆，謝謝。
謝謝醫生細心的解釋, 收穫滿滿!
柴柴好可愛!😍😍
感謝您的收看😉
很感謝張醫師講解！👍👍👍👏👏👏
感謝您的收看🙏
謝謝醫師的詳細解釋
謝謝收看😊😊
解惑了，謝謝醫師。
感謝收看😁
感谢分享这个信息很重要
感謝您的收看🤓
請問張醫師，我有自費去醫院做一些檢查 ，維生素D 30.5。血鐵質 300.73 ，單位ng/ml，B-12 618.8 pg/ml，
我平常的保健品有在吃阿利他命A25，這樣子會有影響嗎？請問張醫師，我該注意什麼，還是有什麼建議，謝謝你。
需要對您做完整評估才能給實際建議，不過一個原則是，有肝腎疾病跟其他慢性病的人，不適合補充過多維他命B 12
謝謝張醫師的回覆,感恩.
谢谢分享关於vitamin B12，最近有市面上介绍的日本保健品，里面有其中一个成份vitamin B12-cyanocobalamin-氰钴胺素，请问这vitaminB 12是安全使用吗？
是的，這就是我說的氰基B12
好醫師！
感謝您的收看😁
感謝醫師
感謝您的收看🥰
那劑量一天要吃多少才可以呢
同問
b12浓度过高，主要原因还是身体有问题，所以才这样，正常是排出的
營養補充品大多是5-1000微克
如果沒有其他身體問題，這種劑量不太容易讓濃度太高
B12的藥物劑量經常遠遠超過1000微克
不適合長期吃，並且建議監測血中濃度
因為生病的關係我每天都補充兩次高單位B12，每星期再加打B12一次😅
缺乏的話，還是要補充
請問醫師，B群是在飯後吃，還是空復吃好，謝謝
飯前飯後都可以，因為他們不需要油脂
所以每个人应要清楚自身健康狀況！什么食物可食及不可食,有怀疑的先要查清楚,因別人的超級食物,对你可能是超級毒物😮
你的意思是如果肝臟有問題肝便大量釋放B12，腎臟有問題便排不走過量的B12是嗎？那麼肝腎功能正常是否補充了過量的B12便沒問題，是嗎？
如何去監測血中濃度，是去醫院還是哪裡呢？請提供資訊參考
維他命B12的檢驗是標準檢驗 幾乎所有的大小醫院都可以提供
@張適恆醫師 謝謝
但食物中的b12含量，是否有簡單的計算參考，不同食物來源的b12的型態有沒有參考資料呢
除了氰基其他的B12都可能存在食物裡面，100公克的雞蛋有四微克，100公克的牛肉有三微克
資料來源 www.commonhealth.com.tw/article/86897
想請問張醫師，在搜尋國外網站可以買得到的 B 群補充品，發現國外的 B 群基本上都是做大劑量的，想請問張醫師這是為什麼呢？
因為B群都是水溶性的，所以大部分都可以快速排出，但裡面的B12還是要小心
那柴犬是真的嗎？😊
是真的🐕🐕🐕
👍👍👍
感謝您的收看😺
爲什麽我一吃甲鈷胺就頭疼，，因爲從小不吃肉嘛。
張醫師，您好：
在
ruclips.net/video/NLYIriHJTB4/видео.htmlsi=2wJ1t0JoQ8aimdeQ
影片8：44秒，說b群中
只有b12 過量是“排不出”，
這是對的嗎？
（如果依您的分析，應該是 腎功能差的人 比較有機率 會 排不太出）
再次謝謝您 專業的分享
@@bomohang 這樣說不對，B12的確會在肝臟中儲存，但大部分吃進去的B 12是被細胞排掉的
謝謝 您的分享 與 回覆
(因為 家母 剛好 有 重度CkD 加藥物性肝硬化 正在努力康復的路上，
所以 正如你影片中 所說 如果真的要 補充B12，
一定要 配合 血檢，再次謝謝 您的專業分享)
氫氧基是否adeno?
是hydroxylcobalamin
👍🙏
太學術性了.
太多醫學專門名詞,
一般人都聽不明白.
不如直接一些, 有那些食物富含 B12 吧.
請看影片，這並不是在介紹哪些食物富含B12。而是在回答一些補充B12相關，非常關鍵的問題。的確本片在我的頻道算是較為深奧，但我相信聽得懂的人非常多喔😊
此部教學影片怎麼沒有聲音？
記得要把聲音打開
太困難了解😂
可以直接跳到6:47之後的部分略過前面的生化課喔
我還未吃B12前是540pmol/L 看來我不能吃B群了
一定要注意血中濃度喔
B12 食用機轉好複雜！
超級複雜😅😅😭😭
非常感謝張醫師專業詳細分析。 我最近一個月口腔牙肉、舌頭和嘴唇都會腫脹痛，舌頭刮損，我吞咽和說話困難。令到我非常困擾和擔心身體出現什麼問題。我剛做了維生素B 12血液測試。我的濃度超標，Conv. Unit：3982pg/ml. Ref. Range: 187-883. S.I. Unit:2938 pool/L. Ref. Range: 138-652. 請問我這樣的指數是否影響我口腔舌頭牙齦牙肉和嘴唇腫脹痛的問題？ 或我應在做什麼檢查? 請問可如何減低我身體內維生素B 12的濃度？ 期待你的答覆，謝謝。
謝謝醫師