CommunityDosing & Titration

Experiences with Vitamin D Injections: Dosing and Side Effects

18 replies11 peopleJun 9, 2026☆ Follow
Summary

What dosing and side effects have people experienced with Vitamin D injections?

Users with absorption issues like gastric bypass report getting prescribed injections that raised levels effectively with no immediate problems. Overdose symptoms from excess buildup include nausea, confusion, fatigue, and potential kidney damage, as seen in one case from misread oral dosing. Bloodwork beforehand is repeatedly advised, and some note injections helped maintain ranges longer than pills alone. Sun exposure and oral options are suggested by others as simpler alternatives.

What this discussion establishesWhere people disagree

Whether sun exposure or oral supplements suffice versus needing injections, and how seriously to weigh rare but severe risks like heart calcification.

Still open

Specific safe injection dosing amounts for different individuals

Nothing here is advice.

18 replies · 11 people
KeenQuill44archiveopening postJun 9

Anyone currently on or who has tried Vitamin D shots? How did you dose them and what side effects showed up?

IronQuill38archiveJun 10

Dose is unclear to me. Still, levels should be tested first before starting anything. Also, why go for shots instead of just swallowing a pill?

NorthThistle12archiveJun 10
↳ replying to @KeenQuill44 (opening post)

Check bloodwork first and stick with a supplement. No need to complicate it when simpler options work. Too much vitamin D can bring some nasty side effects.

NorthThistle12archiveJun 10
↳ replying to @GreyAlder39

Death would take far more than that and is uncommon. Long before reaching that point other issues appear first like nausea, vomiting, appetite loss, constipation, extreme thirst, frequent urination, weakness, tiredness, confusion, muscle and bone pain, plus kidney damage.

CopperAlder51archiveJun 10

Overdosing is possible since vitamin D is fat soluble and accumulates. Symptoms include lethargy and mental confusion among others. It happened to me after low levels led to a prescription of high-dose capsules. I took them daily by mistake instead of weekly. After four days I felt wrecked and had to explain poor work performance to my boss, who figured I was having a breakdown. Vitamin D needs care, so know your starting point and exact amounts required. This was only with pills.

GreyAlder39archiveJun 10
↳ replying to @NorthThistle12

The original post gave no details on the intended injection amount. Last year an elderly person developed heart calcification from prolonged excess intake. Such cases are rare enough to make news. Downplaying the risks could mislead someone new into thinking there is no danger.

QuietFenwick11archiveJun 10
↳ replying to @KeenQuill44 (opening post)

Get your levels checked then buy the pills from a local pharmacy.

RustSignal76archiveJun 10
↳ replying to @QuietFenwick11

A doctor would likely prescribe a strong oral dose if deficiency shows up. When I was low I took one pill weekly.

KeenQuill44archiveJun 11
↳ replying to @IronQuill38

My system does not take it in well and levels stay low.

KeenQuill44archiveJun 11
↳ replying to @QuietFenwick11

Thanks for the sarcasm. No need to question why I want it, that was not asked.

AmberWillow79archiveJun 11

I received two injections with no problems. Levels moved from just above the bottom of the range to the upper quarter where my doctor aimed. After the first shot oral supplements kept things steady for over a year until they dropped again, so another injection was done before they fell too far.

RustMarble34archiveJun 11

My functional medicine doctor gave me 0.5 ml shots twice a week. Started this week and felt no side effects so far. Not sure if combining it with my other injection on the same day caused bad sulfur burps and diarrhea lately or if a stomach bug is to blame.

KeenQuill44archiveJun 11
↳ replying to @KeenQuill44 (opening post)

My doctor prescribed the vitamin D injection but the dose makes me nervous after hearing various reports, which is why I asked. I also get a monthly B12 shot from the same doctor.

SharpAnchor92archiveJun 11

Are you maximizing time outside in non-peak sun for natural production? People make vitamin D from UVB rays rather than from food or supplements.

KeenQuill44archiveJun 11
↳ replying to @SharpAnchor92

No, gastric bypass back in 2007 means my body still struggles to absorb vitamins even from over-the-counter versions. I stayed slim for years until my sister died, then a rough mental period led my doctor to start Paxil and I regained most of the weight. Vitamin levels stayed problematic though. I am on Tirzepitide but that is separate. I wanted more details on the vitamin D shots specifically.

SharpAnchor92archiveJun 11
↳ replying to @KeenQuill44

Your reply does not make sense to me. The body is meant to produce vitamin D itself, not absorb it. Gastric bypass would not affect that process. Lack of time outdoors does. Look up reliable medical sources if your doctor has not covered this.

AmberWillow79archiveJun 11
↳ replying to @KeenQuill44

If the doctor prescribed the shots there is likely a solid reason, and gastric bypass does raise deficiency risks. Advice to get more sun does not always solve it. I garden for hours daily in direct sun wearing minimal clothing and still deal with low levels. Genetic factors can also impair conversion. Not everyone reacts identically. Sorry about your sister and hope levels reach the right range.

KeenSignal28archiveJun 11

Levels were checked every three months over two years. Five thousand IU daily turned out to be the right amount for me. My son tested three times and landed on the same daily dose for good results. When my daughter was deficient she took ten thousand IU daily for two months then dropped to five thousand for upkeep. That dose works across the family per three different doctors. Five to thirty minutes of sun can produce the equivalent of four hundred to one thousand IU, enough to avoid problems but often short of optimal. Since many of us already inject for best results this seems useful to note.

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