Vitamin D intake and multiple sclerosis risk in the Norwegian Mother, Father and Child cohort, 2025, Kapali et al.

[SNT Gatchaman]

Vitamin D intake and multiple sclerosis risk in the Norwegian Mother, Father and Child cohort

Spoiler: Authors

Akash Kapali; Anne Kjersti Daltveit; Kjell-Morten Myhr; Kjetil Bjornevik; Karine Eid; Marte-Helene Bjørk; Anne Lise Brantsæter; Trond Riise; Marianna Cortese

BACKGROUND
Higher vitamin D has consistently been associated with a lower multiple sclerosis (MS) risk, but some controversy remains about whether this is due to vitamin D itself or sunlight.

METHODS
We conducted a prospective study among women participating in the Norwegian Mother, Father and Child Cohort Study, recruited in 2002–2008 and followed until 2022. We identified incident MS cases through data linkage with the Norwegian MS Registry. Total vitamin D intake from food and supplements was obtained from validated food frequency questionnaires completed in pregnancy. We estimated HRs for MS and 95% confidence intervals (CI) using Cox regression.

RESULTS
Among 78 074 participants, 349 developed MS during follow-up. Their median daily vitamin D intake was 296 international units (IU) compared with 333 IU among women who did not develop MS. Higher total vitamin D intake was associated with a 42% lower MS risk (HR comparing top vs bottom quintile 0.58, 95% CI 0.38 to 0.89, ptrend<0.01). The results were similar when adjusting for age at delivery, total energy intake, pre-pregnancy body mass index and smoking. The associations were similar for vitamin D intake from food (HR for top vs bottom quintile 0.70, 95% CI 0.47 to 0.1.04, ptrend=0.02) and supplements (HR for ≥600 IU/day vs <200 IU/day 0.65, 95% CI 0.41 to 1.04, ptrend=0.01).

CONCLUSIONS
In this prospective study, higher vitamin D intake was associated with lower MS risk in women living in Norway, where there is insufficient sun-induced vitamin D production during most of the year. This supports the hypothesis that vitamin D itself modifies MS risk.

Web | DOI | PDF | Journal of Neurology, Neurosurgery & Psychiatry | Paywall

 

[Midnattsol]

The difference in median intake is not particularly high. For reference the typical supplemental dose sold in Norway is 400IU/10mcg.

The associations were similar for vitamin D intake from food (HR for top vs bottom quintile 0.70, 95% CI 0.47 to 0.1.04, ptrend=0.02) and supplements (HR for ≥600 IU/day vs <200 IU/day 0.65, 95% CI 0.41 to 1.04, ptrend=0.01)

This throws me. The highest intake from food would likely not be close to intake og someone who supplements, so if you find an association between the highest and lowest quintiles for food but not supplements then a) the dose needed for the effect is lower than the lowest supplement or b) other nutrients in the food that also contains vitamin D might be responsible for the effect. Vitamin D is found mainly in seafood which include other relevant nutrients such as selenium and omega 3s.

 

[Utsikt]

Did they correct for date of birth to account for sum exposure during pregnancy?

What about place of birth? Northern Norway gets substantially less sun than the south.

 

[Mij]

The D-lay MS trial had their participants take 100,000ius every 2 weeks for 24 months.

Conclusions and Relevance Oral cholecalciferol 100 000 IU every 2 weeks significantly reduced disease activity in CIS and early relapsing-remitting MS. These results warrant further investigation, including the potential role of pulse high-dose vitamin D as add-on therapy.

 

[Dolphin]

The difference in median intake is not particularly high. For reference the typical supplemental dose sold in Norway is 400IU/10mcg.


This throws me. The highest intake from food would likely not be close to intake og someone who supplements, so if you find an association between the highest and lowest quintiles for food but not supplements then a) the dose needed for the effect is lower than the lowest supplement or b) other nutrients in the food that also contains vitamin D might be responsible for the effect. Vitamin D is found mainly in seafood which include other relevant nutrients such as selenium and omega 3s.

Not sure why you are saying this when the associations for food and supplements were very similar?

The associations were similar for vitamin D intake from food (HR for top vs bottom quintile 0.70, 95% CI 0.47 to 0.1.04, ptrend=0.02) and supplements (HR for ≥600 IU/day vs <200 IU/day 0.65, 95% CI 0.41 to 1.04, ptrend=0.01)

 

[Utsikt]

Not sure why you are saying this when the associations for food and supplements were very similar?

The associations were similar for vitamin D intake from food (HR for top vs bottom quintile 0.70, 95% CI 0.47 to 0.1.04, ptrend=0.02) and supplements (HR for ≥600 IU/day vs <200 IU/day 0.65, 95% CI 0.41 to 1.04, ptrend=0.01)

Wouldn’t you expect a stronger association with the higher dose (i.e. supplements)?

 

[Utsikt]

The D-lay MS trial had their participants take 100,000ius every 2 weeks for 24 months.

Conclusions and Relevance Oral cholecalciferol 100 000 IU every 2 weeks significantly reduced disease activity in CIS and early relapsing-remitting MS. These results warrant further investigation, including the potential role of pulse high-dose vitamin D as add-on therapy.

Made a thread:

https://www.s4me.info/threads/high-dose-vitamin-d-in-clinically-isolated-syndrome-typical-of-multiple-sclerosis-2025-thouvenot-et-al.47427/

 

[Dolphin]

Wouldn’t you expect a stronger association with the higher dose (i.e. supplements)?

Perhaps (though the post I replied to didn’t seem to say that) though perhaps only a fraction of it is properly absorbed and active if co-factors from appropriate food aren’t ingested at the same time? Lots of supplement studies in general (not specifically on vit D) seem to have poor results.

 

[Mij]

We need sufficient levels of magnesium for converting vit D into its active form. I had very low vit D levels over 25 years ago but taking supplements didn't help much until I took magnesium shots and my D levels went up by taking 1000iu to 2000iu/daily.