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Hrmbee OP t1_j5065zz wrote

From the article:

>The study is a reanalysis of the VITAL trial, a large-scale project that tested whether proactively taking vitamin D or marine omega-3 supplements could reduce older people’s risk of developing cancer and cardiovascular disease. The randomized, placebo-controlled trial was led by researchers from the Brigham and Women’s Hospital in Massachusetts, which is affiliated with Harvard University. It overall found no significant effect from either type of supplementation on these outcomes. But some data also indicated that vitamin D supplementation was associated with benefits in those with a BMI lower than 25 (BMI between 18.5 to 25 is considered “normal”), specifically a smaller risk of developing cancer and autoimmune disease, as well as a lower cancer mortality. > >To better understand this link, some of the same researchers decided to study blood samples taken from over 16,000 volunteers over the age of 50 involved in the trial. These samples allowed them to look at people’s total vitamin D levels as well as other biomarkers of vitamin D, like metabolic byproducts and calcium, before the study began. About 2,700 of these volunteers also came back for follow-up blood tests two years later. > >The team found that people’s levels of vitamin D and these biomarkers generally increased following supplementation, no matter their BMI. But this increase was significantly less pronounced in those with a BMI over 25, the threshold for overweight and obesity. This dampening effect was also seen in people who had low levels of vitamin D at baseline, meaning those who would experience the greatest benefit from supplementation. The team’s findings were published Tuesday in JAMA Network Open. > >“We observed striking differences after two years, indicating a blunted response to vitamin D supplementation with higher BMI,” said study author Deirdre Tobias, an associate epidemiologist in Brigham’s Division of Preventive Medicine, in a statement from Harvard. “This may have implications clinically and potentially explain some of the observed differences in the effectiveness of vitamin D supplementation by obesity status.”

These are some interesting results, and it's good that researchers went back to look again at the data in this study. Perhaps with more research in this area, weight-based guidelines for dosage could be developed subsequently.

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turtle4499 t1_j527kdx wrote

>BMI over 25, the threshold for overweight and obesity

That is not what a BMI of 25 is. A BMI of 25 is the cut off for where there is a LOW PROBABILITY of being obese and having a bmi lower than that number. I really cannot understand why this is so damn hard for Drs and the general public to get correct.

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Lionscard t1_j52937e wrote

I agree with you on doctors but grasping statistics is an incredibly rare ability for the general public

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turtle4499 t1_j52a609 wrote

Probably because we gear too much math education on calculus and not enough on basic statistics. While you may need calc to derive stats you don't need it to understand stats.

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Hugh-G-Rection-Jr t1_j53hfev wrote

Uh a BMI of 25 is the cut off where you are no longer in the normal range and get overweight and not obese, obesity starts at a BMI of 30. The BMI represents a way to quntify risks a person may have based on their weight, not the probability of them “being obese”, the article mashed up overweight and obesity because of the recent trends of getting fatter and having more people with higher BMI (at least in europe). Also you didn’t finish your sentence “and having a bmi lower than that number” what?

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turtle4499 t1_j54omxc wrote

>Uh a BMI of 25 is the cut off where you are no longer in the normal range and get overweight and not obese, obesity starts at a BMI of 30.

Again no its not. That's what I am telling you. BMI does NOT tell you if an individual is obese or not obese it tells you the percentage chance that someone is obese or not obese. The number is a gross oversimplification and always has been. Obesity is defined by body fat percentage. Sources that define obesity via BMI are 99.999999% of the time misquoting there usage in population studies.

At a population level because we know MOST people with a BMI of 35 are obese you can use that to separate out obese and non obese people. The 25 cutoff range is used because its very hard to be obese and have a BMI below 25.

As I stated this is something drs get wrong all the time and it causes this nonsense.

Here is the CDC who is properly describing BMI.

>BMI can be a screening tool, but it does not diagnose the body fatness or health of an individual.

And

>The accuracy of BMI as an indicator of body fatness also appears to be higher in persons with higher levels of BMI and body fatness. While, a person with a very high BMI (e.g., 35 kg/m2) is very likely to have high body fat, a relatively high BMI can be the results of either high body fat or high lean body mass (muscle and bone). A trained healthcare provider should perform appropriate health assessments to evaluate an individual’s health status and risks.

BMI is thus a indicator of odds of being obese and not a indicator of being obese except at the high ranges because at those ranges the odds of being obese increase high enough that few who get by are rare. At 35 you would be passing someone like brock lesnar/ dwayne johnson as obese. They are roided to the gills and would be a low percent of people with a BMI of 35 or above.

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OrneryLawyer t1_j55evcx wrote

You are really invested in stressing that someone high BMI might not be an obese person.

Sure, buddy. Anyone with eyes can tell if your 30 BMI body is due to being like the Rock or you know, just being a fat slob.

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turtle4499 t1_j55h6ux wrote

And when you make a study where you don't get pictures of the 10k people in it just using BMI doesn't give you the visual information. Congrats you figured out the problem.

BMI has a variable positive predictive value understanding what ranges are good for what situations is important. You would not want to use the same scores for screening patients that you would for measuring risk factors of obesity.

The closer you are to the lower bound there is a reduction in confidence. Which is why in research associating things related to being fat you don't use the 25-30 cutoff because it has too many false positives. Which systematically biases that population to have understated risks of being overweight. Studies that use better adjusted obesity numbers have confirmed this effect.

BMI at a cutoff of 25 is not intended to have low false positive rate its intended to have low false negative rate. Thats why its called a SCREENING TEST. Because almost 100% of people with obesity will have a BMI above 25 that includes many people particularly in the 25-30 range that are not obese. The range that is used is purposefully over capturing because that leads to better screening.

I am really invested in stressing the proper use of BMI. Because using it incorrectly is what causes people to ignore the number out of hand. This is a science sub where people discuss science like proper understanding of the statistical meaning of a BMI score.

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OrneryLawyer t1_j55mg3n wrote

You are overthinking this. If a patient stands in front of you with a 30 BMI, will you be able to tell at a glance if the person is obese or not?

What causes people to ignore the number out of hand is not "incorrect use of BMI," it's self delusion.

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Hugh-G-Rection-Jr t1_j55p008 wrote

Maybe someone hurt him with the BMI? I mean you need serious mental gymnastics to go over the point and overcomplicate a basic information that much… “incorrect use of BMI” and the whole study thing really nailed it for me, from where I am only fatasses that can’t cope with being fat say crap like that. Look I know this sounds hard but the people who made this stuff know a lot better than someone on reddit who is fixating on a borderline score that would give a false pozitive/negative, really man? Really? You think people with a bmi of 25.2 are going to go insane because they are classed as overweight (25-30 means overweight, like in a little bit over? not obese or going to die just a little fluffy?). I hope in the next comments he gets what screening test actually means and stop saying 25-30 is obese, please link me where cdc says that on the BMI 25 is obese not overweight also that obesity starts at 25 not 30 (TWO TOTALLY DIFFERENT THINGS) and I’m giving in my practice licence tomorrow morning. Please tell me all studies are perfect and please tell me a serious study where if there even aren’t pictures you don’t have staff to evaluate the subjects.

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Hugh-G-Rection-Jr t1_j55pfaj wrote

My bad, “society that bases too much on calculus and not enough on statistics” - while shitting on a statistic discovered and worked upon from 1850 while citing what fits the anti dr, anti scientists “i know better without having the slightest ideea what the numbers I’m ready represent” is pretty much explanatory to why. Also the real reason why that number is the way it is isn’t because false results, look down the street and tell me 3/5 people aren’t fat…

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SerialStateLineXer t1_j58vn89 wrote

What do you mean by "obese?" The medical definition is having a BMI in excess of 30. Arguably this is not a very good definition, but it's the definition that's used. So when you say that BMI is an imperfect proxy for obesity, it's not really clear what you mean by "obesity." Are you talking about a body fat percentage threshold? Waist circumference? Waist height ratio?

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neontrotski t1_j50e3ax wrote

That’s interesting. Just last night I was looking at medical literature, strongly suggesting that vitamin D has a role to play in intestinal health therefore immunity system stuff and it affects the lungs, like asthma. AND ALLERGIES.

So deficiency in vitamin D is super common and it can help you catch asthma and allergies and food, sensitivities, etc.. Definitely worth learning about guys.

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diagnostics247 t1_j50h7b4 wrote

I have been taking a vitamin D supplement for years. I am chronically low on vitamin D. I am obese, have horrible allergies, and IBS.

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G2chainz t1_j50m4af wrote

Do the supplements help at all?

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diagnostics247 t1_j514z7l wrote

Not really, but I continue to take it daily to help my psoriatic arthritis and prevent long term complications such osteoporosis.

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Pragya_S t1_j516sjd wrote

Hey, does your Vit D supplement has magnesium also? Apparently for Vit D absorption, the body needs adequate amount of magnesium.

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smallgovisbest t1_j50ae3n wrote

The study was based upon a 2,000iu/day supplementation.

I would like to see a study that uses much higher dosage levels for overweight/obese individuals. I'd like to see the effects of high dose intravenous vitamin D, as well as high dose oral supplementation (20,000+ iu) for individuals with low blood serum levels. It's understood that vitamin d can be stored into fats, thereby reducing the amount of vitamin D that makes it into the blood system. Therefore, the effects this study points to may be related to an under dosing for overweight individuals.

I am interested in seeing a study focusing on the best methods to raise an individual's blood serum levels of vitamin D to at least 50 ng/mL.

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Moont1de t1_j50el9y wrote

The issue with increasing the dose is that you're increasing the amount that gets stored in fat, which can lead to hypervitaminosis when the stored vitamin D inevitably gets released. I don't think such a study is ethical.

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jupitaur9 t1_j50k8rt wrote

Is there any IV vitamin D therapy available? Would it be practical?

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Bierkerl t1_j5211cb wrote

I went to the doctor in late December for my annual physical. The only abnormal test was low vitamin D, so she put me on an 8 week plan. Once each week I take 50,000iu that I had to get from a pharmacist, plus 2,000iu (over the counter) every day for 8 weeks.

I'm on week 4 now and don't feel any different and haven't had any side effects, but hopefully my level will be in the normal range when I go back. I have no idea why it would be low. I eat all kinds of foods that I've since found out have it, including drinking milk. We'll see how things go!

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palox3 t1_j51oot5 wrote

yes there is. my mother used to take vid d by injections

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Hrmbee OP t1_j506k4a wrote

A direct link to the journal for those who are interested:

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2800490

Key Points:

>Question Does body weight modify metabolism and response to vitamin D supplementation?
>
>Findings In this cohort study, a subset including 16515 participants of the VITAL randomized clinical trial, established and novel vitamin D serum metabolite levels were on average lower at higher body mass index. Supplementation increased vitamin D levels less over 2 years at higher body mass index.
>
>Meaning Previous trials observed reduced efficacy of vitamin D supplementation for outcomes of cancer, diabetes, and others, in subsets of participants with higher body mass index; the findings of this cohort study suggest this may be due to a blunted metabolism and internal dose at higher body weights.

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eat_vegetables t1_j537xrw wrote

More evidence is great. However, this is already a known clinical phenomenon.

From a 2018 Biochemistry textbook:

>Lipoprotein lipase, particularly in adipose tissue, acts upon chylomicron lipids and may result in a fraction of the vitamin D being taken up by fat cells. This observation suggests a mechanism whereby increased adiposity causes sequestering of vitamin D and is related to lower vitamin D status (IOM, 2011). Indeed, adipose tissue sequestration of vitamin D represents a nonspecific process, and these stores may not be actively used in periods of need (IOM, 2011). Thus obese individuals may require higher intakes of vitaminD to achieve serum concentrations of 25-hydroxyvitamin D (25OHD) comparable tothose observed among lean individuals (IOM, 2011).

Stipanuk, M. H., & Caudill, M. A. (2018). Biochemical, physiological, and molecular aspects of human nutrition-E-book. Elsevier health sciences.

Primary:Institute of Medicine. (2011). Dietary Reference Intakes for calciumand vitamin D. Washington, DC: The National Academies Press.

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T00MuchStimuli t1_j51zmmk wrote

It’s fat soluble. Have you ever tried traveling through fat?

Way harder than wading through a swimming pool.

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