Can vitamin D harm?

What do cardiovascular diseases, cancer, bone health and the risk of falls have in common?



Taking vitamin D prophylactically does not have any positive effect on them.



I send those interested to read the results of a large prospective study VITAL .



But sometimes doctors feel a sacred need to prescribe something in order to meet the patient's expectations. Placebo pills work better than placebo pills. Vitamin D is great for this role. Its deficiency is common. Replenishment is easy. There are many preparations for every taste, color, smell and consistency. You can always come up with a fanciful design scheme to add a touch of expertise to yourself. Side effects are extremely rare. Cases of hypercalcemia and kidney damage have been reported when fanatics drank doses of D3 beer mugs while sunbathing, but this is casuistry. So why not appoint, if it doesn't get worse and there is a chance to make a person better?



Or could it be worse?



Curious researchpresented at the Congress of the American Society of Bone and Mineral Research [ASBMR 2020]. The authors planned to assess whether high doses of vitamin D have a positive effect on bone tissue in healthy people. We recruited 311 volunteers without osteoporosis with a 25 (OH) D level of more than 30 nmol / L, who consumed ~ 1200 mg of calcium per day. The average age is 62 years, half of the men. The volunteers were randomized into 3 groups, who were given 400, 4,000 and 10,000 units of D3 per day. The study lasted 3 years. Every 3-6 months, a bunch of laboratory and instrumental indicators of the state of phosphorus-calcium metabolism and bone tissue were assessed. By the end of the study, the average vitamin D levels in the groups were 76.3, 132.2 and 144.4 nmol / L, respectively.



As expected, the revolution did not happen - no positive effect on bone tissue was found . An unexpected turn happened in the fact that at high doses of vitamin D, the indicators of bone tissue became worse. According to high-resolution computed tomography for 3 years, the loss of BMD in the radius was 1.8% vs 5.5% in the 400 U and 10,000 U D3 groups, respectively. There were no significant differences in men.



The authors comment that it is safe to say that there is no benefit from high doses of D3. Potential harm needs to be confirmed in further studies with large numbers of volunteers. Based on the increase in b-CrossLaps, it is assumed that active metabolites in the presence of excess D3 can activate osteoclasts and provoke bone resorption. True, it is not entirely clear why only women. Let's see what will happen next. Noteworthy.



The magicians on Instagram will say that the doses of D3 were just small. And the 25 (OH) D level cannot be trusted. Determined by the same ELISA method. The result should be divided by 2. God forgive me.



For those interested in the topic, I advise you to watch my video about vitamin D, where I analyze whether there is any benefit from it.