High‑dose vitamin D significantly reduces disease activity in early multiple sclerosis onset, clinical trial finds (100,000 IU doses)

Medical Xpress / JAMA ^ | March 24, 2025 | Justin Jackson / Eric Thouvenot et al

[ConservativeMind]

Researchers have found that oral cholecalciferol in doses of 100,000 IU every two weeks significantly reduced disease activity in clinically isolated syndrome and early relapsing‑remitting multiple sclerosis.

Multiple sclerosis typically starts with an acute episode involving the central nervous system, such as inflammation of the optic nerve, the spinal cord, or brainstem syndromes. This combination of initial signs is termed a clinically isolated syndrome (CIS), although CIS does not always convert to MS.

In the D‑Lay MS randomized clinical trial, investigators conducted a parallel, double‑blind, placebo‑controlled study comparing high‑dose cholecalciferol versus placebo in untreated CIS.

Eligibility criteria included adults aged 18–55 with CIS onset within 90 days, serum vitamin D <100 nmol/L, and MRI evidence of dissemination in space or ≥2 lesions plus positive oligoclonal bands.

A total of 316 participants were randomized 1:1 to receive oral cholecalciferol 100,000 IU (n=163) or matching placebo (n=153) every two weeks for 24 months. The primary outcome was disease activity (first relapse or new/contrast‑enhancing MRI lesions). Of the 316 randomized, 303 (156 vitamin D; 147 placebo) received at least one dose and 288 completed the full 24‑month follow‑up.

Disease activity occurred in 94 of 156 patients (60.3%) receiving vitamin D versus 109 of 147 (74.1%) receiving placebo (HR, 0.66), and median time to disease activity was significantly longer with vitamin D (432 vs. 224 days).

All three secondary MRI outcomes favored vitamin D: overall MRI activity (57.1% vs. 65.3%; HR, 0.71), new or enlarging T2 lesions (46.2% vs. 59.2%; HR, 0.61), and contrast‑enhancing lesions (18.6% vs. 34.0%; HR, 0.47).

Oral high‑dose cholecalciferol reduced disease activity in CIS and early relapsing‑remitting MS. These findings support further investigation, including pulse high‑dose vitamin D as an add‑on therapy. High‑dose vitamin D may offer an inexpensive, well‑tolerated option, especially where access to standard disease-modifying therapies is limited.

[mass55th]

"I have taken over 10,000 IU per day for years and years with absolutely NO ill-effect, but have excellent health for someone who is 80+."

Keep doing what you're doing. Sounds like it works. I'll be 78 this year, the good Lord willing.

[mass55th]

"I read that if you take more than 4,000 IU D3 daily, you need to also take K2 so that calcium is used correctly and does build up on arteries. The MK-7 type of D3 is recommended."

I had to stop taking Calcium supplements many years ago because they found out I have a hyper para-thyroid that produces more calcium than my body needs. My calcium levels are always high in my bloodwork. Other than taking out those glands if it gets worse, there's nothing they can do about it.

[hflynn]

10,000 IUs of vitamin D can become a serious problem unless a doctor is lab testing your blood on a regular basis.

[aimhigh]

what about Vit D toxicity?

Vitamin D toxicity is usually associated with Vitamin D2, not D3. D2 is big pharma's artificial version.

[TTFX]

My calcium levels are always high in my bloodwork.

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Excess retinol (a type of vitamin a) can cause that. We don’t need to take vitamin a supplements because foods have enough. Some brands of milk and multivitamins have retinol supplements. More info:

Hypercalcemia and vitamin A
https://www.ccjm.org/content/89/2/99.long

[mass55th]

"Hypercalcemia and vitamin A https://www.ccjm.org/content/89/2/99.long"

Thanks for the link.