cross-posted from: https://feddit.it/post/25171235
23 Male, microcytic.
On 11/11/2025 I had blood tests done prescribed by my family doctor because I was experiencing problems with lack of strength/general asthenia. The tests showed that I have a serious vitamin D deficiency; specifically, my levels are at 10 ng/mL. The tests also showed slightly elevated levels of albumin (69%) and Folic Acid (31.1 ng/mL), but according to my doctor, these are not cause for alarm.
I want to point out that in the spring of this year, for the first time in my life, I set myself the goal of walking 10,000 steps a day, and I did so every day before lunch (between 12:30 and 1:30 p.m.). In fact, during this period, I exposed myself to the sun for about 40 minutes every day, and I have never felt so good in my entire life. I was able to study without any problems, and I also trained four times a week for two and a half hours. I started having these occasional weakness issues during the summer, when I must admit that I didn’t expose myself to the sun much because I suffer a lot from the heat (I live in Italy). So I really think my problem is related to low vitamin D levels, and I would like to feel like I did during that period again.
Since I didn’t feel comfortable with this doctor, I stopped seeing him and a doctor friend of mine recommended me to take 8000 I.U. of vitamin D daily.
I started to take the vitamin D approximately 5 days after the tests, let’s say I started the 11/16/2025.
The first two weeks I took some simple vitamin D (two 4000 IU tablets) and then, for another two weeks, I started taking a Vitamin D3 + K2 supplement purchased from Prozis, as my doctor friend had advised me to also take vitamin K2 to help transport calcium to the bones. Each capsule of this supplement contains 100 μg of vitamin K and 2000 IU of vitamin D3, so I took 4 capsules.
About two weeks after 11/16/2025, when I started the supplement, I began to feel more intense muscle pain than usual during my gym workouts and a more pronounced sense of fatigue all day along. So I decided, on my own, to reduce my Vitamin D3 supplementation. Recently, I have continued to take Vitamin D3 + K2 supplements, but the dose varies from 1 to 2 capsules (2000-4000 IU).
Essentially, what I noticed was that:
- If I take 8000 IU a day, after 2-3 days the muscle pain and fatigue return at the gym
- If I take 2000 IU per day for a week, I feel pretty good (although not like in the spring), but if I forget to take the supplement one day, after 2-3 days I experience episodes of severe muscle weakness, which prevent me from studying or doing other daily activities.
This month I changed my family doctor and explained this situation to her. She prescribed me a 50,000 IU vitamin D supplement to take once every two weeks. But I’m afraid that taking such a large dose all at once will cause the same problems I have when I take an 8,000 IU dose, if not worse.
So I would like to know, in your opinion, what is the daily dose of vitamin D I should take, and whether muscle pain and general fatigue can actually be linked to vitamin D3 or vitamin K2 supplementation, or to an increase in calcium in the muscles.
P.S. My calcium levels in blood are 9.9 mg/dL.
Rule 5. Locking.
I feel since you are experiencing side effects at certain doses you should discuss this with a doctor, not in online forums.
4k a day overtime is when you can get toxicity…
Most supplements are a tenth of that, and doctors usually won’t recommend over 600/day…
You say you were taking 8k a day bro.
Even the 50k/14 days is just under when toxicity normally happens. But it’s probably because you’re pushing to take an absolutely insane amount and she wanted to first get you under the limit.
So I would like to know, in your opinion
Stop fucking asking random people and listen to your doctor.
The reason your blood levels is normal, is all that calcium is forming kidney stones. Those will be incredibly painful, and will teach you the lesson if you haven’t learned it in a couple years.
Vit D is one of the easier vitamins in that you have to take ridiculous amounts over a long period for it to be a problem, while really small doses once in a while can still be helpful.
1000mg daily is considered a lot and is used for treating a high/severe deficiency. Despite not being deficient to a diagnostic degree I take a pill now and then (every few days, whenever I remember) to make sure I’m not deficient, since my region doesn’t really get any sunlight this time of year. I guess it averages out to maybe 200mg daily.
Not a doctor and I don’t have an exact answer to your question, but this might be helpful:
This may not be a thing in Italy, but check if you’re actually able to get enough vitamin D naturally all times of the year where you are.
if you live in northern England near where I am, for example, you can only really guarantee you’ll get your RDA of vitamin D from the sun during the summer months. I believe in north Scotland it’s not ever possible to reliably get enough naturally.
I try to take a 3000/4000 (honestly which one depends what’s on offer) more or less daily outside of summer. During summer I still take them but maybe every few days.
I would probably try what your doctor recommends (assuming you’ve already flagged your specific concerns, otherwise I’d do that first), it’s entirely possible the 50,000 pill is formulated in such a way it manages to be (somewhat incredibly) slow release. If you experience any issues, schedule an appointment as soon as you can, so they can do some tests to help figure out what’s going on. Your doctor has a degree in this stuff, so it’s good to try what they suggest and discuss any changes with them
This also might not be much of an issue for you since I assume you’re getting your supplements from the same, trusted place. But if not, there’s a load of fake and low quality supplements out there, make sure you research the brand you’re getting has been tested and had its contents verified independently. Any issues could be down to unexpected adulterants rather than the vitamin dose itself
Thank you for your response. I’ll look into my Vitamin D brand.
Removed by mod
You might think you’re helping, but if anyone is naive enough to listen to you, they’re going to have painful and relatively serious medical complications…
Maybe I should’ve clarified something, in that I wasn’t taking into account bad quality vitamin D3 supplements, as OP might have had a bad quality supplement.
That makes no sense and you’re still both telling people to take dangerous amounts of supplements.
If what you’re trying to say is the products you just recommended by name lie and really contain waaaaaaaaaay less and that’s why you’re able to take so much…
Then you should just recommend people take normal dosages from brands that can be trusted.
Or better yet, stop recommending medical advice to anyone, because anyone stupid enough to listen to you will suffer real harm.
Take that shit back to Facebook or tiktok
Is that not why I disclaimed that I wasn’t a doctor? That was my experience with D3, and I thought it’d work well for OP.
