The main concern to be aware of is that if taking high doses of vitamin D (10000+ IU daily for weeks), then you could start to get calcification (of arteries, heart, kidney, pineal gland…) IF you have inadequate magnesium and vitamin K2 levels, which are also common deficiencies. Dr. Berg has a short new video explaining all the concerns worth being aware of:
https://www.youtube.com/watch?v=gjJdzHIwDDU
Magnesium is SO worth supplementing with anyway, especially magnesium L-threonate, easily my favorite single nootropic.
Vitamin K2 is a tricky one, it’s very hard to know if you have adequate levels, as it depends on your body’s ability to convert K1 to K2, your gut bacteria’s level of production of it, and your foods sources (not that many foods contain K2).
It’s also important to consider your levels and sources of vitamin A. Synthetic A is typically not great. Liver is the best source (I use cod liver oil as a vitamin A supplement taken maybe once a week or less, and occasionally eat cow liver).
One of the best ways to find a doctor is through IFM. Functional medicine is a great model. It treats the person not the symptoms.
https://www.ifm.org/
For those who don’t want to have to go through a doctor there is an easy home blood spot test kit that you can mail in to check your level. Costs $65 plus shipping.
https://daction.org/start
One interesting thing from the Mercola report is that he says that ALL of the studies that say Vitamin D doesn’t work tested specific doses and NOT blood levels. It’s all about how much you absorb not how much you take. So when you see the media downplaying the usefulness just remember how they twist the facts.
Four years ago, I had my yearly physical. As part of that, I had an extensive blood test workup. The test showed that my blood Vitamin D was very low. I was surprised that I was deficient because I am retired and spent several hours daily outside working. Research showed that vitamin D deficiency is common. Too much sun is bad for you so we mostly cover up and use sun screen (I do not use sun screen). Older people (like me) have less efficient vitamin D production. I was put to 50,00 iu of Vitamin D3 weekly. After 6 months my insurance refused to cover it and required the OTC strength version (400 iu) at a dose of 1 per day. I’s cheap. I needed it. I have been taking it since that time. At last years yealy physical, my Vitamin D blood level was not checked. I asked about that and was told that it was no longer a test routinely covered by insurance. I asked about having the test and paying for it myself. I was quoted about $260.00. By the way, the new senior citizen health care also does not cover EKGs, colonoscopy, or prostate check. For the senior ladies, no more PAPs. I was told that the cost of these checks was not worth the money and not worth the potential rewards. So much for preventative care. Currently my wife and I both take 2,000 iv of Vitamin D3 daily. I do need to get our vit D blood levels checked tio see where we are. Everything in this country is becoming politicized and monetized.