This article has some info. that was new to me, mainly about
how other nutrients affect vitamin D levels. I hope it's helpful!
tinyurl.com/kmn2pj7Here's the paragraph where he talks about
other nutrients, in case some of you can't read through the whole thing.
"I believe the literature is clear that many of the symptoms associated with vitamin D toxicity are actually related to other nutrient deficiencies—vitamin K2 deficiency specifically. When you take supplemental vitamin D, you increase your body’s need for vitamin K2, so when supplementing with oral vitamin D3, you need to make sure you’re also increasing your K2 and magnesium intake. The biological role of vitamin K2 is to help move calcium into the proper areas in your body, such as your bones and teeth. It also helps remove calcium from areas where it shouldn’t be, such as in your arteries and soft tissues. So vitamin K2 deficiency is actually what produces the symptoms of vitamin D toxicity, which includes inappropriate calcification that can lead to hardening of your arteries".