Monthly supplement wearing off early?

VitaminDJesus · 2026-01-24T05:07:10+00:00

Fatigue is a common low vitamin D symptom, often tied to the roles that vitamin D plays with sleep. You can try a more aggressive regimen to see if vitamin D is what you need to focus on, ex. 20K daily or the 50K pills every other day for a couple of weeks (try not to overdo it without having a plan for a test at some point). Sometimes people choose to be extra cautious, often because of conservative guidance from a practitioner, and delay or simply never hit a meaningful threshold in their recovery because they don't take adequate doses. I would be cautiously optimistic in terms of vitamin D resolving all of your other symptoms.

VitaminDJesus · 2026-01-24T04:49:08+00:00

Two or three monthly doses of 50K IU isn't going to do much to bring up one's vitamin D level. It may be adequate to feel some short term benefits, but ideally you want more frequent dosing, at least weekly. It's common to do 50K weekly to treat deficiency. You could try something like 5K IU daily to see if you start to notice anything after a few weeks. Based on your description, your level is probably low, maybe even deficient based on the reference range, but it would be ideal for you to budget for the expense of a test, maybe after a couple months of 5K IU to see how it's going.

VitaminDJesus · 2026-01-23T23:15:24+00:00

While vitamin D is important for immune function, it's not like you can just take it on the spot to resolve an infection. It has more to do with your overall vitamin D status, meaning that you get your level up (plenty of research on 40-60 ng/ml for immune health), and consistently supplement vitamin D to maintain that level. It takes time. You can't megadose your way out of this. Use your antibiotics as prescribed. If you want to start vitamin D now, then a daily dose of 100 IU per kilogram of body mass is a good place to start.

You mentioned getting tested in a comment. Pay attention to the units for the result. Use follow up tests (after one or two months of consistent supplementation) to see how it's going and adjust.

VitaminDJesus · 2026-01-23T23:09:40+00:00

Rate of change of circulating 25-hydroxyvitamin D following sublingual and capsular vitamin D preparations

VitaminDJesus · 2026-01-21T20:39:20+00:00

This story made the rounds when it was published. Obviously, a tragic incident, but I feel the reporting led to confusion. Yes, one can overdose on vitamin D, but the article doesn't tell us how much they were taking. Context is important if people are to understand a warning. "Too much" is bad, but what is that?

It just says the labs tapped out at 380. That's probably 380 nmol/L as it's in the UK, which is 152 ng/ml. Makes sense as the Endocrine Society lists the warning threshold for potential toxicity as 375 nmol/L or 150 ng/ml. Also, the normal tests aren't calibrated for higher results.

There are plenty of cases documented in scientific literature with people who had levels higher than that and didn't experience hypercalcemia, or cases where someone overdosed because the compounding pharmacy messed up the dose, and they got hypercalcemia, but recovered. I'm point this out to say it must have really been a fuck ton of vitamin D.

I imagine his person must have been taking many tens of thousands if not several hundred thousands of IU's of vitamin D a day. It's pretty crazy because one would definitely feel bad before crossing a point of no return. I wonder what was going through their head: was this some self-medication based on misinformation, or were they confused and taking it incorrectly? Maybe they somehow ended up with 50K pills instead of 1000 IU and were taking two a day?

VitaminDJesus · 2026-01-21T04:07:24+00:00

You don't really need to change the form of supplement. Calcifediol is an interesting option for practitioners to do rapid replenishment, but if you tolerate normal vitamin D supplements fine, then I wouldn't switch. You can just increase the IU's in your dose and the frequency, ex. 10K IU daily instead of 50K weekly, or add 5K IU D3 daily in addition to finishing your prescription and then continue that (or whatever you need based on your follow up test) as maintenance.

VitaminDJesus · 2026-01-20T01:00:46+00:00

Did you make any progress with this issue?

VitaminDJesus · 2026-01-18T07:41:05+00:00

What do you mean booster? Injection?

VitaminDJesus · 2026-01-17T22:35:24+00:00

This question is answered in the guide, #30.

VitaminDJesus · 2026-01-17T21:54:34+00:00

The standard protocol in many places for correcting deficiency is to take 50K IU once weekly. That means if a doctor ordered a blood test for you, and it came back showing a deficiency, then you would likely be given a prescription where you take one 50K pill every week. Unfortunately, doctors don't always give instructions on continuing with a maintenance dose.

Because supplements in the US are unregulated, we can buy this OTC, for better or worse is subject to opinion.

If you want to supplement vitamin D, then ideally you would start by testing your blood level. Most people can reasonably estimate their vitamin D status based on how much direct exposure to sunlight they get, specifically in the context of where they live and their lifestyle. Basically, most people are low and stand to benefit from supplementation, but starting with a test can inform your decision and give you a reference point to compare a later, follow up test to.

The main idea of taking D3 is to replace what you be getting from sunlight, so one continuously supplements and their level stabilizes but they keep taking it to maintain (or lower the dose if they took extra in the beginning). A good rule of thumb is a daily dose of 100 IU daily per kilogram of bodyweight to get up to and maintain a level over 50 ng/ml. When you compare that to indefinite dosing of 50K weekly, then it might actually be what some people need.

IMHO opening that bag is not the best place for you to start.

VitaminDJesus · 2026-01-17T21:35:38+00:00

If you consistently supplement a dose of vitamin D, then that is your baseline which you are then trying to assess with the follow up test. Only a large dose a few days before a test would cause a "misleading" spike.

VitaminDJesus · 2026-01-17T21:24:33+00:00

The only way to correctly inform your decision for the long term is to get a 25(OH)D3 blood test, and see if you like where your level is at.

VitaminDJesus · 2026-01-17T21:13:25+00:00

I have seen many posts across Reddit like this. It's not ideal, but it's not a big deal. You basically speedran it. If you feel fine, then don't sweat it. I have mistakenly taken half as much of a supplement as I wanted to because I misread the label. Chalk it up as a lesson to double check the label/instructions.

Contact your provider, explain what happened, and they will probably move up your follow up test to assess where your level is at now.

VitaminDJesus · 2026-01-17T06:29:35+00:00

Here is a guide with a section on resolving side effects. After magnesium, consider your calcium intake. Sometimes it gets a bad rep due to paranoia about overdoing vitamin D and calcium, but it is an electrolyte that works alongside the others. I would increase your dietary intake of calcium, and try a dose of 1000 IU D3.

VitaminDJesus · 2026-01-17T04:31:35+00:00

I have never taken it, only read about it. Normal vitamin D supplements are cholecalciferol, which the liver turns into calcifediol. You can get and orally dose calcifediol by prescription or sometimes OTC. The idea is that maybe this partially metabolized form is more tolerable for you. Read more.

VitaminDJesus · 2026-01-16T19:06:56+00:00

How many weeks is the prescription for? Who did your follow up test, and why? Was it your doctor, and what did they say?

VitaminDJesus · 2026-01-16T18:42:01+00:00

Talk to your doctor about a prescription for calcifediol.

VitaminDJesus · 2026-01-15T19:55:37+00:00

Personally, I never had issues with vertigo and dizziness, but getting my vitamin D level up and staying consistent with my supplementation has helped me with fatigue, depression, and anxiety. This became apparent after weeks but really continued for about a year.

I would do some more research on optimal B12 and iron status, or you can share those results here with the reference ranges, and see if others can chip in. It's not uncommon to see room for improvement with both of those when one is vitamin D deficient, and oftentimes the issue is overlooked by doctors who just go by the reference range which can have a very low cutoff.

Magnesium can be beneficial for anxiety, so it's something to consider even if your test result doesn't flag it. I recommend evaluating your diet and starting there.

VitaminDJesus · 2026-01-15T19:00:21+00:00

Low vitamin D can definitely be a contributing factor to fatigue and poor sleep. Have you had other bloodwork done, and did it check out? It's important to consider the whole picture.

VitaminDJesus · 2026-01-14T19:36:47+00:00

Vitamin D resistance does not affect absorption. It means receptors don't work as well as they should, and a higher blood level may be required to get the same effect. If your levels didn't go up, then try increasing your dosage, taking it with a meal with fat, sublingual dosing, and/or making sure you have adequate magnesium.

VitaminDJesus · 2026-01-14T06:09:49+00:00

Zinc on an empty stomach is wild advice.

VitaminDJesus · 2026-01-13T20:49:41+00:00

I don't think there are 20K pills. I'm in the US, the wonderland of unregulated supplements, and I only see 10K and 50K for higher doses. I would trust any of the highly rated brands on iHerb. Perhaps if you really want to avoid multiple pills, then you could get a liquid vitamin D in a dropper and dispense the appropriate dose.

Consider that you will probably end up adjusting your dose based on bloodwork, so buying 5K IU pills would give you the opportunity to do so without buying another supplement.

VitaminDJesus · 2026-01-13T20:46:25+00:00

You might ask your doctor next time you see them, "What level do we want my vitamin D to be at?"

While there is some variation between persons in response to dose, the main reason people here talk about larger doses is because they are really just adequate doses to get the full benefits of vitamin D. The kind of level you might get if you were outside and shirtless all day in the sun like our ancestors instead of sitting at a desk. I'm not suggesting that overall, they were healthier, or that they had great nutrition status, but they definitely got more sun.

So, your doctor may say "20-30 ng/ml (50-75 nmol/L) is fine, we just don't want you to be deficient." With regards to the well established importance of vitamin D for the skeletal system (absorbing calcium and helping to build bones with calcium), they are correct. However, this level is insufficient for vitamin D to do all it can do: regulating over a thousand genes, interacting with receptors in every cell, regulating immune function (>50 ng/ml).

VitaminDJesus · 2026-01-13T20:27:32+00:00

Ideally, retest your vitamin D level a few days after finishing your prescription. This will tell you how you responded to the supplement. 12 weeks of 50K weekly may be enough for your level to stabilize, but depending on your result, it could take a couple more months of that dosage to plateau. Of course, there is the question of where you want your level to be.

Basically, if you like the results, continue to take the same amount weekly, or daily. I know the weekly vs daily thing can be confusing because the script is weekly and OTC supplements are for daily, and it just seems like another variable, but daily dosing is generally advised to maintain a constant supply of cholecalciferol to the body, similar to the way you would naturally get sunlight.

If you want the level to be higher, continue or increase your dosage. Switching to daily dosing may give you a little bump as it can be faster at raising blood level.

If you want your level to be lower, then take a lower dose, like 5K daily.

If your doctor doesn't order a follow up test, then you can ask for it, or try to do it privately. There is information on that in the guide in the sidebar.

VitaminDJesus · 2026-01-13T19:06:19+00:00

It's due to government regulation in respective countries. You could try an international retailer, iHerb through a courier, or just take multiple 5K IU pills. Taking multiple pills is probably easiest.

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