#102 为什么维生素D缺乏会加速大脑衰老

医生。

Doctor.

我是隆达·帕特里克。

Rhonda Patrick here.

一项新研究发现，补充维生素D与十年内痴呆风险降低百分之四十相关。

A new study found that vitamin D supplementation was associated with a forty percent lower risk of dementia over a decade.

仅仅五年后，服用维生素D补充剂的人中有百分之八十四没有患痴呆，而非服用者中这一比例为百分之六十八。

After just five years, eighty four percent of the vitamin D supplement users were dementia free compared to sixty eight percent of the non users.

这项研究涉及超过一万两千人。

This was a study of over 12,000 people.

对于有轻度认知障碍且携带APOE4基因的成年人，维生素D将痴呆风险降低了约百分之三十三。

And vitamin D reduced dementia risk by around thirty three percent in adults with mild cognitive impairment and also had APOE4.

这是神经退行性疾病的一个关键遗传风险因素。

This is a key genetic risk factor for neurodegenerative diseases.

多达百分之二十五的人口携带这种等位基因之一，如果携带其中一个，患阿尔茨海默病的风险会翻倍。

Up to twenty five percent of the population has one of these alleles, and it can double the risk of Alzheimer's disease if you have one of them.

如果你有两个这样的等位基因，患阿尔茨海默病的风险可能高出十倍。

If you have two of these alleles, you can have up to a tenfold higher risk of Alzheimer's disease.

维生素D不仅仅是一种维生素。

Vitamin D is not just a vitamin.

维生素D会在体内转化为一种类固醇激素，调控我们身体中超过一千个基因。

Vitamin D gets converted into a steroid hormone that regulates over a thousand genes in our body.

它进入细胞核，激活或抑制接近5%的人类蛋白质编码基因的表达。

It enters the nucleus of our cells and it regulates, it activates and turns on, or it suppresses and turns off up to nearly 5% of the protein encoding human genome.

这非常关键，因为高达70%的美国人处于缺乏或不足的水平。

This is very relevant because up to seventy percent of Americans fall into a range known as deficient or insufficient.

因此，近30%的美国人实际上缺乏维生素D。

So almost thirty percent of Americans actually are vitamin D deficient.

他们的25-羟基维生素D水平低于每毫升20纳克。

They have levels of twenty five hydroxyvitamin D below twenty nanograms per milliliter.

另外约40%的人则处于不足的水平。

The other forty percent or so has levels that's known as insufficient.

这些人的维生素D水平高于每毫升20纳克，但低于每毫升30纳克。

So these are people that have vitamin D levels above twenty nanograms per milliliter, but they're below thirty nanograms per milliliter.

避免这种缺乏和不足其实有一个简单的解决方案，那就是服用维生素D补充剂。

And there's really a simple solution to avoiding this deficiency and insufficiency, and that is a vitamin D supplement.

通常，维生素D缺乏的人每天服用2000到4000国际单位，就能达到足够的水平。

Usually, people that are vitamin D deficient, if they take around two thousand to four thousand IUs per day, they can get to a sufficient level.

维生素D缺乏和不足之所以如此普遍，有很多原因。

There's a lot of reasons why vitamin D deficiency and insufficiency is so widespread.

这是因为我们在皮肤暴露于太阳的紫外线辐射时，会在体内合成维生素D。

That is because we actually make vitamin D in our skin upon exposure from UV radiation from the sun.

因此，任何阻挡UVB辐射的因素，也会阻碍我们皮肤合成维生素D3的能力。

So anything that blocks out UVB radiation is also going to block out the ability to produce vitamin D3 in our skin.

这包括防晒霜。

That includes sunscreen.

还包括皮肤色素沉着。

It also includes skin pigmentation.

因此，黑色素是一种较深的色素，它作为天然防晒剂，也会削弱身体利用UVB辐射合成维生素D3的能力。

So melanin, this is the darker pigmentation that serves as a natural sunscreen that also blunts the body's ability to make vitamin D3 from UVB radiation.

年龄。

Age.

随着年龄增长，身体从日晒中合成维生素D3的效率和效果会降低。

As you get older, your body is less efficient and effective at producing vitamin D3 from sun exposure.

事实上，70岁的人从阳光中合成的维生素D只有20岁的人的四分之一，这和你住在哪里有关。

In fact, a 70 year old makes four times less vitamin D from the sun than a 20 year old where you live.

因此，在北纬地区，一年中的许多月份，根本没有任何UVB辐射到达大气层。

So living in a northern latitude, many months of the year, actually, there's no UVB radiation even reaching atmosphere.

因此，生活在较高纬度地区的人们，在一年中的很多个月里都无法通过阳光在皮肤中合成维生素D3。

So people that are living in more northern latitude areas are not able to make vitamin D3 in their skin from the sun for many, many months out of the year.

这也极大地影响了维生素D的合成能力。

So that also really affects the ability to make vitamin D.

还有体脂。

And then also just body fat.

维生素D实际上是一种脂溶性维生素，它储存在脂肪中。

So vitamin D is actually a fat soluble vitamin, and it's stored in fat.

因此，你体内的脂肪越多，意味着可供释放到血液中的维生素D3就越少，而维生素D3需要在血液中进一步代谢转化为类固醇激素，这种激素才是真正调控包括大脑在内许多基因的物质。

And so the more body fat that you have, that means the less vitamin D3 is bioavailable to be released into the bloodstream where that it undergoes further metabolic conversion to the steroid hormone, which is actually what's regulating all these genes, many of them in the brain.

现在，我们将更深入地探讨这项显示痴呆风险降低百分之四十的研究。

Now, we're going to dive a little bit deeper into this study that showed a forty percent lower risk of dementia.

但我想先说明，这并不是第一个发现这一现象的研究。

But I want to mention first that this is not the first study to show this.

事实上，有许多所谓的观察性研究都在探讨维生素D水平低下与痴呆风险之间的关联。

I mean, there are many, many, many what are called observational studies that are looking at a correlation between low vitamin D levels and dementia risk.

许多不同的研究都发现了同样的关联。

Many different studies have found this same association.

因此，有人可能会说，维生素D缺乏的人可能整体健康状况更差。

And so one might say, well, people that are vitamin D deficient might just be less healthy.

他们可能更少晒太阳。

They might be going out in the sun less.

他们运动得更少了。

They're exercising less.

因此，维生素D缺乏可能只是其他健康因素的生物标志。

And so vitamin D deficiency might just be bio marking some other health factor.

所以，我认为这是一个相当相关的论点。

So that is a, I would say, pretty relevant argument.

但我们还有大量其他数据支持维生素D缺乏与痴呆风险及阿尔茨海默病风险之间的关联。

But we also have a whole host of other data to support the link between vitamin D deficiency and dementia risk and Alzheimer's disease risk.

例如，在这些观察性研究中，我们可以研究一种叫做孟德尔随机化的方法。

So for example, with these observational studies, we can look at what's called Mendelian randomization.

这是一种利用遗传学来研究环境因素如何影响结果的方法。

This is a way to use genetics to look at how something in the environment can affect an outcome.

在这种情况下，有许多不同的基因调控着人体产生维生素D3并将其转化为类固醇激素的能力。

In this case, there's many different genes that regulate the ability of your body to produce vitamin D3 and convert it into the steroid hormone.

有些人由于这些基因存在某种变异，导致其效率较低，无法很好地完成这一过程。

And some people do that less effectively because they have a certain variation in those genes that are not doing it quite as well.

因此，你可以观察基因导致的维生素D水平低下。

And so you can look at genetically low vitamin D levels.

换句话说，你只需查看某人的基因。

In other words, you just look at someone's genes.

如果他们携带某种影响维生素D转化效率的基因变异，我们就将他们归入低维生素D组，因为我们知道携带这些基因的人确实维生素D水平较低。

And if they have a certain variation of that vitamin D converting gene that makes it not as effective, you put them into the low vitamin D group because we know people with those genes actually do have low vitamin D.

然后你将他们与那些拥有正常功能基因、不会导致维生素D水平低下的人进行比较。

And then you compare them to people that have the normal functioning genes that don't make them have low vitamin D levels.

他们体内的25-羟基维生素D——即实际的类固醇激素——水平并不低。

They don't have low one hundred twenty five hydroxyvitamin D, which is the actual steroid hormone.

然后你观察他们患痴呆症和阿尔茨海默病的风险。

And then you look at the risk for dementia and Alzheimer's disease.

研究发现，基因导致的维生素D水平低下会使痴呆风险增加高达54%。

And so what's been shown is that genetically low vitamin D levels increase dementia risk by up to fifty four percent.

这再次证实了观察性数据，而这类数据本身并不能真正证明因果关系。

Again, this is really confirming that observational data, which really can't really show causation.

因此，这加强了这些数据，但你可以更进一步，查看其他研究表明维生素D缺乏实际上会加速大脑衰老。

And so it strengthens that data, but then you can go a step further and you can look at other studies that have shown vitamin D deficiency actually accelerates brain aging.

因此，已有研究通过功能性磁共振成像（fMRI）观察了所谓的白质高信号。

So there have been studies that have shown that have looked by fMRI at what's called white matter hyperintensities.

这些白质高信号在脑部MRI图像上表现为小的白色亮点，实际上是大脑白质损伤的标志。

So these kind of show up as little white hyper spots if you're looking at a MRI image of the brain, And it's really a marker of damage to the white matter in the brain.

而白质对大脑功能和信息传递至关重要。

And the white matter is where it's so important for brain function, for communication.

它正是大脑进行通信的方式。

It's how your brain's communicating.

因此，当白质受损时，确实会影响认知功能。

So when you have damage to that white matter, it really does affect cognition.

它会影响沟通和记忆。

It affects communication and memory.

维生素D每增加10纳摩尔/升，这些白质高信号的体积就会轻微减少，表明较高的维生素D水平有助于预防这种类型的大脑损伤。

For every ten nanomole per liter increase in vitamin D, there was a small decrease in the volume of these white matter hyperintensities, suggesting that having higher levels of vitamin D can protect against this type of brain damage.

再进一步，看看维生素D补充剂如何影响认知功能。

Even a step further, looking at vitamin D supplementation and how that can affect cognition.

目前，关于维生素D补充剂对健康成年人认知功能的影响，研究数据存在很多矛盾之处。

Now, there's a lot of mixed data out there, particularly when it comes to vitamin D supplementation affecting cognition in normal healthy adults.

但已有几项研究专门考察了维生素D补充剂在阿尔茨海默病患者或轻度认知障碍人群中的作用。

But there have been a few trials that have actually looked at vitamin D supplementation in people with either Alzheimer's disease or people with mild cognitive impairment.

在这两种情况下，如果患者每天服用约800国际单位的维生素D，持续一年，他们在多个认知领域——包括记忆、注意力和整体智商方面——都出现了显著改善。

So both in both those scenarios and people with mild cognitive impairment, if they took around eight hundred IUs of vitamin D daily for a year, they had significant improvements in multiple areas of cognition, memory, attention, overall IQ.

阿尔茨海默病研究也得出了同样的结论。

And the same goes with the Alzheimer's disease study.

那些每天服用800国际单位维生素D超过一年的阿尔茨海默病患者，其记忆和注意力测试得分也有所提升，与我刚才提到的首项研究结果相似。

So people that took, again, eight hundred IUs a day for over a year, and these people were already diagnosed with Alzheimer's disease, they also had improved scores on memory and attention tests similar to that first trial I just mentioned.

此外，研究还发现，血液中与阿尔茨海默病进展相关的淀粉样蛋白β病理标志物，如淀粉样蛋白β42，也出现了减少。

But additionally, there was also a reduction in blood biomarkers of amyloid beta pathology, such as amyloid beta 42, which is associated with Alzheimer's disease progression.

因此，这些数据进一步支持了这样的观点：维生素D水平过低会增加痴呆风险，而补充维生素D则有助于降低这一风险，这也让我们回到最近的这项研究——维生素D补充与痴呆风险降低40%相关。

So this data really strengthens the argument that low vitamin D can increase dementia risk and that supplementing with vitamin D can help lower that risk, which brings us back to this recent study where vitamin D supplementation was associated with a forty percent lower risk of dementia.

让我们更深入地探讨一下这个研究。

So let's dive into that a little bit closer.

这项研究纳入了12,388名成年人，并将他们分为两组。

So the study included twelve thousand three hundred and eighty eight adults who were divided into two groups.

一组报告使用了任何形式的维生素D补充剂，可能是钙维生素D。

Those who reported using vitamin D supplements in any form, it could be calcium vitamin D.

也可能是活性形式的维生素D。

It could be the active form of vitamin D.

也可能是维生素D2。

It could be vitamin D2.

所以任何形式的维生素D，具体是哪种形式并不重要。

So any form of vitamin D, it didn't matter what form.

另一组则是没有服用任何类型维生素D补充剂的人。

And then the other group it was divided into is those that did not take any form of vitamin D supplement.

研究进行了十年的随访，在此期间，补充维生素D与痴呆发病率降低40%相关。

There was a ten year follow-up, and during that period, supplementing with vitamin D was associated with a forty percent lower incidence of dementia.

在从未使用维生素D补充剂的两千多名参与者中，有人员患上了痴呆症，而使用维生素D补充剂的参与者中仅有六百七十九人患痴呆。

Over two thousand participants who reported never using vitamin D supplements developed dementia compared to just six seventy nine of those participants who actually did report using vitamin D supplements.

补充维生素D还与五年无痴呆生存率的提高相关。

Supplementing with vitamin D was also associated with a greater five year dementia free survival.

因此，在维生素D组中，有84%的成年人在此期间未患痴呆，而非维生素D使用者中仅有68%在相同时期保持无痴呆状态。

So eighty four percent of adults in the vitamin D group were free of dementia during this time period, while only sixty eight percent of the non vitamin D users were dementia free during that same period.

而且，无论参与者基线时是否患有轻度认知障碍或认知功能正常，这一结果都成立。

And this was also true regardless of whether or not the participants had baseline mild cognitive decline or normal cognitive function.

因此，维生素D在这两种情况下似乎都提供了益处。

So vitamin D seemed to provide a benefit in both of those scenarios.

尽管轻度认知障碍成年人的痴呆患病率较高，但补充维生素D的群体中，其患病率比未补充者低约15%。

And while dementia prevalence was higher in adults with mild cognitive impairment, it was around fifteen percent lower in this group for adults who supplemented with vitamin D compared to those who didn't.

换句话说，即使你已经存在某种程度的轻度认知障碍，只要补充维生素D，你发展为痴呆的风险仍然更低。

So in other words, even if you already had some sort of mild cognitive impairment, you still had a lower risk of actually transitioning to dementia if you were supplementing with vitamin D.

尽管维生素D补充在所有群体中都降低了痴呆风险，但在某些特定人群中，维生素D的益处仍有一些有趣的发现。

Although vitamin D supplementation reduced dementia risk among all groups, there were several interesting findings regarding the benefits of vitamin D for certain populations.

例如，女性从维生素D中获益最大。

So, example, for women derived the greatest benefit from vitamin D.

她们患痴呆的比例实际上低于补充维生素D的男性。

They actually experienced less dementia compared to men who supplemented.

虽然使用维生素D的男性比不使用者的痴呆发病率低26%，但使用维生素D的女性比不使用的女性发病率低近50%。

And while vitamin D using men had a twenty six percent lower dementia incidence than non users, Vitamin D using women had almost a fifty percent lower incidence compared to non using women.

因此，女性发病率降低的差异要大得多。

So really, there's a much bigger difference in terms of women having a lower incidence.

我在想，这是否是因为一般来说，女性患痴呆和阿尔茨海默病的频率大约是男性的两倍。

And I'm wondering if that's because, generally speaking, women get dementia and Alzheimer's disease about twice as higher of a frequency than men do.

所以，这里可能有更大的下降空间。

So there just might be more of a signal here to lower.

这是一种可能性。

That's one possibility.

基线认知功能正常的成年人，如果补充维生素D，痴呆发病率降低56%；而已有轻度认知障碍的成年人，补充维生素D后痴呆发病率仅降低33%。

Adults that had normal baseline cognitive function had a fifty six percent lower dementia incidence if they supplemented with vitamin D, but adults that did have mild cognitive impairment only had a thirty three percent lower incidence of dementia if they supplemented.

换句话说，如果你一开始没有痴呆且身体健康，维生素D在降低痴呆发病率方面效果更显著，这很合理。

So in other words, if you were already if you started out dementia free and healthy, vitamin D had a more robust effect on lowering your dementia incidence, which makes sense.

如果你已经处于轻度认知障碍状态，要逆转已经造成的损伤就困难得多。

If you're already in a state of mild cognitive impairment, it's much harder to kind of reverse damage that's already been done.

这就引出了APOE4基因。

And this brings us to APOE4.

我之前提到过，APOE4是阿尔茨海默病最大的遗传风险因素。

So I mentioned earlier, APOE4 is the biggest genetic risk factor for Alzheimer's disease.

百分之二十五的人口至少携带一个等位基因。

Twenty five percent of the population carries at least one allele.

携带一个等位基因会使痴呆和阿尔茨海默病的风险增加两倍。

Having one allele can increase the risk of dementia and Alzheimer's disease by twofold.

携带两个该等位基因则可能使风险增加十倍。

Having two copies of that allele can increase the risk up to tenfold.

因此，人们必须清楚，如果他们携带其中一个等位基因，就应尽一切可能通过生活方式来降低痴呆风险。

So it's really important for people to understand that if they have one of these alleles that they really need to try to do everything they can within their lifestyle to lower their dementia risk.

因此，携带ApoE4基因且补充维生素D的人，其痴呆发病率降低了约33%。

And so people that had ApoE4 that supplemented with vitamin D did reduce their incidence of dementia by around thirty three percent.

而在非携带者中，维生素D将痴呆发病率降低了47%，略高一些，这并不令人意外。

And among non carriers, vitamin D reduced the incidence of dementia by forty seven percent, a little bit higher, which is not surprising.

但仅靠补充维生素D并不能完全抵消携带一个或两个ApoE4基因副本所带来的影响，这些参与者患痴呆的风险仍比非携带者高出16%，即使那些非携带者并未使用维生素D。

And supplementing with vitamin D wasn't enough to outweigh the effects of carrying one or two copies of ApoE4, these participants still had a sixteen percent greater risk of dementia than non carriers, even non carriers who didn't use vitamin D.

另一个风险因素——轻度认知障碍——同样如此，即使在补充维生素D的情况下，其痴呆发病率仍比认知功能正常的人高出近400%。

The same was true for another risk factor, having mild cognitive impairment, which elevated dementia incidence by nearly four hundred percent compared to people that had normal cognitive function, even in the presence of vitamin D supplementation.

换句话说，如果你在基线时携带APOE4基因或已有轻度认知障碍，那么你患上痴呆和阿尔茨海默病的风险会显著升高。

So in other words, you if you have an APOE4 allele or if you had mild cognitive impairment at the baseline, then you just you had a tremendously higher risk of getting dementia and Alzheimer's disease.

然而，维生素D补充仍然起到了一定的帮助作用。

However, the vitamin D supplementation did still help.

但它对健康且认知功能正常、非携带者的保护效果，远比对上述高风险人群的效果要好。

It just didn't help as much as someone that was healthy and had normal cognitive function and was a non carrier at the start of this study.

好的。

Okay.

让我们再深入探讨一下。

So let's dig a little bit deeper.

未补充维生素D的轻度认知障碍参与者，其患痴呆的风险比具有正常认知功能的成年人高出六倍以上，即使那些成年人也没有使用维生素D。

Participants with mild cognitive impairment who didn't supplement with vitamin D had more than a six hundred percent increase in dementia risk compared to the adults with normal cognitive function, even those who didn't use vitamin D.

换句话说，我刚才提到，与试验开始时认知功能正常的人相比，患有轻度认知障碍的人患痴呆的风险高出四倍。

So in other words, I just mentioned that people that had mild cognitive impairment had a four hundred percent higher risk of having dementia compared to people that had normal cognitive function at the beginning of the trial.

但这是在他们补充了维生素D的情况下。

But that was only if they supplemented with vitamin D.

如果一开始就患有轻度认知障碍且未补充维生素D，那么他们患痴呆的风险会高出六倍。

People that didn't supplement with vitamin D had a six hundred percent higher risk of developing dementia if they started with mild cognitive impairment.

维生素D的使用形式也不重要。

It also didn't matter what form vitamin D was used.

所有形式都与较低的痴呆风险相关。

All of them were associated with a lower dementia risk.

具体而言，使用钙加维生素D与痴呆风险降低44%相关，而使用维生素D3则与痴呆风险降低37%相关。

Specifically using calcium vitamin D was associated with a forty four percent lower risk of dementia, and using vitamin D3 was associated with a thirty seven percent lower risk of dementia.

而使用维生素D2（植物来源）则与降低百分之五十的痴呆风险相关。

And then using vitamin D2, which is the plant version, was actually associated with a fifty percent lower risk of dementia.

使用复合形式的维生素D与降低百分之五十的痴呆风险相关。

Using combined forms of vitamin D was associated with a fifty percent lower risk.

因此，在总结时，我认为不仅本研究的发现，还有我之前提到的其他研究，都强有力地支持了这样一个观点：每个人都应该至少补充一些维生素D，以避免缺乏。

So I think here in concluding thoughts, overall, not only the findings of this study, but the other studies that I talked about really do give strong support to this idea that everyone should probably be supplementing with at least some vitamin D to make sure they're avoiding deficiency.

正如我之前提到的，缺乏维生素D在美国是一个普遍存在的问题。

And I mentioned as I mentioned earlier, deficiency is a widespread, you know, problem in The United States.

高达百分之七十的人要么缺乏，要么不足。

Up to seventy percent of people are either deficient or insufficient.

所以，做一次简单的血液检测是你能做的最好的事情之一。

So getting a simple blood test is one of the best things you can do.

检测你的25羟基维生素D水平。

Measure your twenty five hydroxy vitamin D levels.

这是活性类固醇激素125羟基维生素D的前体。

This is the precursor to the active steroid hormone, one hundred twenty five hydroxyvitamin D.

你希望你的25羟基维生素D水平保持在三十到六十纳克每毫升之间，我认为这是一个非常理想的维生素D水平。

And you want to have your 25 levels between, you know, thirty to sixty nanograms per milliliter is a great, I would say, level to have your vitamin D levels.

你最好不要超过八十纳克每毫升，否则就进入偏高的范围了。

You don't really want to go above eighty nanograms per milliliter, then you start getting into a pretty high range.

大多数人每天服用两千到四千国际单位的补充剂，具体取决于你的血液水平，就能将维生素D水平维持在四十到六十的范围内。

Most people can take a supplement in the range of two thousand to four thousand IUs a day depending at where your blood levels are at and keep their vitamin D levels within that, you know, 40 to 60 range.

因此，建议每年做一次维生素D血液检测，以确保你没有服用过量，或者确认你摄入的量足以将水平提升到理想区间。

So it's good to kind of do an annual vitamin D blood test just to make sure you're not taking too much or to make sure that you're actually taking enough to raise your levels into that sweet spot.

最后，我想谈谈维生素D如何支持大脑健康。

And lastly, I just want to mention how vitamin D can support brain health.

维生素D可以促进淀粉样蛋白β的清除。

So vitamin D can enhance the removal of amyloid beta.

它通过促进这种蛋白从大脑中排出，来降低其与阿尔茨海默病的关联。

This is a protein that's linked to Alzheimer's disease by promoting its efflux from the brain.

在之前提到的那项研究中，是一项随机对照试验，参与者每天服用八百国际单位的维生素D，而他们本身已经患有阿尔茨海默病。

Now, I mentioned in that study, it was a randomized controlled trial in people that were giving an eight hundred IUs of vitamin D a day, people that already had Alzheimer's disease.

它降低了他们体内的淀粉样蛋白斑块负荷。

It lowered their amyloid beta plaque burden.

维生素D也是一种免疫调节剂。

Vitamin D also is an immune modulator.

因此，大脑中小胶质细胞和星形胶质细胞上的维生素D受体有助于减少过度的神经炎症。

So vitamin D receptors on microglia and astrocytes in the brain help reduce excess neuroinflammation.

它基本上有助于降低大脑中的促炎细胞因子反应。

So it basically helps lower the pro inflammatory cytokine response in the brain.

我们知道，神经炎症在痴呆症和阿尔茨海默病的发病中起着至关重要的作用。

We know that neuroinflammation plays a major, major role in the cause of dementia and Alzheimer's disease.

维生素D还能上调多种神经营养因子，包括神经生长因子和脑源性神经营养因子。

Vitamin D also upregulates a variety of neurotrophic factors, including nerve growth factor and also brain derived neurotrophic factor.

这有助于支持神经递质，促进学习和记忆。

So this is helping support neurotransmitters, supporting learning and memory.

最后，维生素D还能减少氧化应激。

And then lastly, vitamin D also decreases oxidative stress.

正如我之前提到的轻度认知障碍试验所显示的那样。

It's been shown in mild cognitive impairment trial that I mentioned earlier.

这是一项随机对照试验。

This was a randomized controlled trial.

那些服用维生素D的人，其各种氧化应激标志物的水平比服用安慰剂的人更低。

Those individuals that took vitamin D also had decreased levels of various markers of oxidative stress compared to people that were given the placebo.

因此，你知道，氧化应激是一种间接方式，可能导致大脑中多种炎症过程。

And so, you know, oxidative stress is an indirect way that can lead to a variety of, you know, inflammatory processes and stuff in the brain as well.

因此，维生素D可以通过多种不同机制支持大脑健康。

So there's several different mechanisms by which vitamin D can support brain health.

而且，进行维生素D检测并服用相对便宜的维生素D补充剂也非常简单。

And again, it's pretty simple to get a vitamin D test and to take a relatively inexpensive vitamin D supplement as well.

我是医生。

I'm Doctor.

隆达·帕特里克，我们很快再聊。

Rhonda Patrick, and I'll talk to you soon.