As with most supplements, ask your doctor. Do a blood test every year. Maybe see a nutritionist.
Vitamin D is ambivalent: as said in the article, it helps calcium absorption so if you're too low on vitamin D you might be too low on calcium and thus have frequent cramps and what not.
But if you're a little too high on vitamin D and consume your fair share of calcium, then calcium absorption could be too high and you'll end up with premature atherosclerosis and other vascular issues.
Vitamin D is ambivalent: as said in the article, it helps calcium absorption so if you're too low on vitamin D you might be too low on calcium and thus have frequent cramps and what not. But if you're a little too high on vitamin D and consume your fair share of calcium, then calcium absorption could be too high and you'll end up with premature atherosclerosis and other vascular issues.
See https://academic.oup.com/ndt/article/27/5/1704/1844110