I tried the keto diet and it didn't cure my problem. But it does seem to have got rid of the acid reflux that seems to have been a persistent problem since I took the Moderna jab, so that's a good.

As for vitamin D, I doubt it would cure lupus, but it makes sense to take supplements if you know it's a potential issue. Then you might find out, I guess. Rarely does supplementation with one nutrient cure anything, except disease caused by a deficiency of that one nutrient.

I found the only thing that helped me was a diet I didn't believe in, but it worked anyway, so I'm a convert to trying weird diets. But then I took drugs to speed things up that reversed the benefit. So I'm personally open to trying anything non-toxic, but I can certainly understand your skepticism.