i imagine the author will have drawn to some degree on both studies to construct the sentence.
on this track at the moment:
Vitamin D3 supplementation and neurofilament light chain in multiple sclerosis (2019)
https://onlinelibrary.wiley.com/doi/abs ... /ane.13185
Low circulating vitamin D levels are associated with an increased risk of active MRI lesions and relapses in several cohorts with relapsing remitting multiple sclerosis (RRMS). Randomized controlled supplementation trials are, however, negative on their primary endpoints, while secondary MRI endpoints suggest anti‐inflammatory effects. Circulating levels of neurofilament light chain (NfL) are a biomarker of disease activity in RRMS. We explored whether 48‐week high‐dose vitamin D3 supplements were associated with lower circulating NfL levels.
Materials & Methods
Of N = 40 Dutch interferon beta‐treated participants with RRMS of the SOLAR trial, plasma samples at baseline and 48‐week follow‐up were available. Of these participants, N = 24 were supplemented with 14 000 IU/d vitamin D3 and N = 16 with placebo. Twenty‐five hydroxyvitamin D3 (25(OH)D3) levels were measured with LC‐MS/MS, and NfL levels were measured in duplicate with Simoa.
Serum 25(OH)D3 levels at 48 weeks were increased in the vitamin D3 when compared to placebo group (median level 281 [IQR 205‐330] vs 72 [39‐88] nmol/L; P < .01). NfL levels at 48 weeks did not differ between the treatment groups (median level 25.4 [IQR 19.6‐32.2] vs 25.3 [17.9‐30.1] pg/mL; P = .74). Higher week 48 NfL level showed a trend toward association with a higher risk of combined unique active lesions on the week 48 MRI scan (OR 2.39 [95% CI 0.93‐6.12] for each 10 pg/mL increase; P = .07).
Supplementation of high‐dose vitamin D3 for 48 weeks was not associated with lower NfL levels. This study does not support an effect of vitamin D3 on this biomarker of neuro‐axonal injury.
4 | DISCUSSION
High-dosed vitamin D3 supplements in interferon beta 1a–treated RRMS did not result in lower plasma NfL levels. This adds to the negative findings of this intervention on clinical endpoints in this study.7
It is also in line with another study, where moderate doses of vitamin D3 supplements did not affect both clinical and NfL endpoints.3,13 These negative results are paralleled by a positive effect of supplements on MRI endpoints.2,7 Therefore, despite these data, vitamin D3 supplementation in RRMS remains a controversial issue