Is the vitamin D supplement you take effective? Professor analyses the difference in activity and inactivity

I published Silicon dioxide on 2025-8-12: Food addition, can it harm immunity? , reader Mr. Chen left a message on 2025-9-2:

I would like to ask the teacher and review the teacher's supplements for vitamin D in the past, and it should be ineffective. However, the active vitamin D supplement drugs that are activated by the doctor in patients with vitamin D deficiency or looseness are effective, but will not the inactive vitamin D of health food become active when taken? Please ask why this difference? Thank you teacher.

Regarding the difference between active and inactive vitamin D, the vitamin D I published five years ago (2020-8-12) is invalid. Is it because I was active? A brief explanation was made. I'll give a more detailed explanation now.

The most important and natural way for us humans to take vitamin D is the sun. The ultraviolet light in the sun will transform the 7-dehydrocolesterol in our skin into "Pre-vitamin D". Then, the temperature of the sun will further transform the "predecessor of Vitamin D" into Vitamin D. This vitamin D has no physiological effect, so it is called "inactive vitamin D".

Another way for us to take vitamin D in humans is to eat certain types of foods, such as fish, eggs, and mushrooms. Vitamin D in these foods is also "inactive vitamin D".

For those who are obsessed with health care products, their main way to take vitamin D is neither sunshine nor food, but to take vitamin D or drips. Vitamin D in these "replenishing agents" is also "inactive vitamin D".

Whether it is vitamin D taken from sunlight, food, or supplements, it will be transformed into 25-hydroxyvitamin D in the liver. This is the main form of vitamin D in the blood circulation, which is the factor that determines whether you have too high or too low vitamin D during blood testing. This transformation step has no control mechanism, that is, all the vitamin D you take will be converted into 25-Rhode Vitamin D. (Note: 25-Directal vitamin D is also called calciferidin or norcin glycol, which is Calcifediol in English)

25-Directal vitamin D will further transform into 1,25-Directal vitamin D (1,25-dihydroxyvitamin D). This is what is called "active vitamin D", and it is also called calcitriol. This transformation process is strictly controlled. When our bodies need more stamina, transformation will accelerate, and when our bodies have enough stamina, transformation will swell.

As long as the vitamin D we take is from sunlight or food, there will be no problem with this controlled operation. However, when the vitamin D we take comes from a supplement, this controlled operation may be problematic. A large amount of vitamin D will cause the control valve to break, resulting in excessive production of "active vitamin D", which will eventually lead to "vitamin D poisoning". Please see:

Vitamin D causes acute kidney failure

Vitamin D poisoning

Vitamin D poisoning, will dog feed recall

Vitamin D become water-soluble? Do you need to work very hard to get poisoned? The truth about vitamin D, the new book published by Mr. Chen, reader of the new book, said that "the active vitamin D supplement medicines that are enabled by doctors are not that simple." Since "active vitamin D" may cause "vitamin D poisoning", doctors who activate active vitamin D must monitor whether the patient has risks of "vitamin D poisoning". Please see the guide to using calcitriol. Please also see my published

Long-term Vitamin D Increases Dementia's risk of death by 2 times

Related Vitamin D and Dementia: Active/Inactive

In contrast, if the patient only takes "Inactive Vitamin D", it may not be able to achieve the "treatment" effect, and the doctor is not responsible for monitoring whether the patient has the risk of "vitamin D poisoning".

Therefore, although "inactive vitamin D may become active after taking it", both "effects" and "risks" cannot be determined. This is the difference between taking "inactive vitamin D" and "open active vitamin D".

Another area is that doctors establish "active vitamin D" as a non-profit picture, but opening or recommending "inactive vitamin D" is a smile.

Original text: Vitamin D: active vs inactive, effective vs poisoning