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Vitamin D Dosage for Immune System?

I’ve been taking 6,700 IU of D per day, my multivitamin with 1,700 and then a 5,000 IU capsule with breakfast. I’ve been doing this for years, in late June I got my blood work and D levels were 47. I usually get sick a couple times in winter, what’s everyone’s thoughts on me taking 10,000 IU a day plus the multivitamin? It seems I’d still be a long way from anything remotely toxic.

Not an expert on the topic but from what I’ve read up to 15,000 iu per day is safe to take. Functional doctors like Dr. Mercola say 60ng/dl is ideal. I recently upped my intake as well from 5000iu to 7000iu per day for the same reason, blood test showed 45ng/dl after taking 5000iu for years.

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Are supplements snake oil? Really just want somebody to chime in? I’ve got 5000 iu vitamin D gel tabs. I haven’t taken them in a while but I work days then nights no sunshine what should I do?

Depends on the supplements. Some supplements can affect absorption of others so I like to buy them individually (vs a multi) and take them at times where they won’t interfere with absorption of others.

I take these daily:
Vit D3 - 5,000+ IU
Vit k2 (mk-7) - 100 mcg
Boron - 3mg+
Magnesium glycinate - 400-600mg
Methylcobalamin (sublingual vit B12) - 1000mcg
Vit C - 2000mg

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I have had low WBC for at least 20 years. I started taking 50,000 units of vitamin D once a week a month ago. I got my labs last week. For the first time my WBC is in range. So I believe there is a connection, at least for now.


I should add I’m doubling the dose with winter coming, way less absorption from sunlight.

I wanna share my story regarding vit d.
When I was a kid I was sick very often and taking anitbiotics every 3-4 months.
As an adult I also got sick at least 2-3 times per year with antibiotics need(very seriously) and 2-3 times more light sick so to say.
I started to optimize vit d last December with big doses - 50-60 000 UI per week. Since then I DIDN’T GET SICK EVEN ONCE! In fact when I started optimizing D I was snowboarding in France, got sick, I took 50 000 units additionally and after 2 days no sign of sickness. Its crazy.
Last February my girlfriend had terrible flue, I had sex with her that time. When she got home to her parents all of them got sick and her father went into hospital. I didnt even got a cold or a single symptoms.

To be honest, I cannot believe that and since then I expect that this is temporary and I will start getting sick again, but it’s almost a year now…

I recently learned vit d is not well absorbed without K2. Not sure how true is that, but I will try optimize this as well.


I wanted to share an update. I saw my doctor last week and asked her about this. She said since my D levels are pretty much middle of the range there was no need to take more. She also said that too much can actually make my body not used to producing enough of something that is crucial to building up calcium which could lead to brittle bones.

I asked a friend of mine who’s a PhD biologist and he echoed similar thoughts. I’m still going to seek more of professional opinions.