your advice is on the money re Mag and calcium. Most DO take too much D3 as well but it’s typically because you need to be sufficient in mag in order to absorb D, therefore, everytime people test their D levels they never go up. Get on a good mag, like glycinate and/or malate and you’ll be able to absorb the D.
I also like iodine and selenium and, as part of that protocol, which also includes mag, should be Vitamin C and a good salt.
For the record and benefit of the OP, the RDA for nutrients is generally only enough to keep you out of the grave. We need much higher doses of most nutrients to make a difference. ie RDA for mag is 450 mg/day but I take 600-900mg/day. Iodine’s RDA is 150mcg (miniscule); I take 12.5-25mg/day
Iodine ping!