I posted previously that studies have been done using a chemotherapy drug (bexarotene) that stimulates vitamin A receptors for dementia rather than using vitamin A itself. The argument for this is usually that the analog may be safer than using the vitamin itself. Of course this claim is never investigated The only rationale I can come up for this is the analog is able to be patented and then sold at MUCH higher prices rather than the vitamin which cannot be patented. Well this same thing has happened before with psoriasis and vitamin D.
Going back as far as the 1980s it has been known that vitamin D can help with psoriasis. However, regular old vitamin D has been discouraged due to the risk of hypercalcemia (high calcium levels in the blood). However, studies never put patients on doses sufficient to do this. In fact most studies looked at doses of vitamin D far below what is known to be safe (a dose of 5000 to 10000 units per day of vitamin D3 is generally accepted to be safe in review of the literature and especially if levels and calcium are monitored). Then, after skipping over oral vitamin D without adequate testing they went straight for topical vitamin D analogs.
There are two main problems with this. First and foremost is cost. A bottle of vitamin D3 can cost as little as 10 dollars. One tube of the most commonly used vitamin D3 analog Calcipotriol (calcipotriene) can cost as much as 300 to 400 dollars.
The second problem is that psoriasis and other skin problems are often a symptom of a full body problem. The skin is just the most visible and noticeable area. Therefore the vitamin D deficiency in these patients must be treated otherwise by lathering a vitamin D analog on the skin you may merely be masking the most obvious symptom of a full body disease.
And this is a common problem with relying solely on the pharmaceutical industry. They are doing their job trying to find effective drugs. However, if they cannot patent the drugs they study they will go broke. So no one can blame them for not studying Vitamin D3. That is not their role. And they do the same with herbal supplements. They do not study turmeric, or ginger, or ginkgo because they cannot patent them. Instead they try to find synthesized chemicals that can mimic their action and patent those.
This is where the government or some type of insurance supported research organization needs to step up. We MUST have research looking at vitamins and herbs and seeing how effective they are and proving if they are safe or not. Then if, for example, vitamin D3 is shown to be effective for psoriasis with few side effects the challenge goes to the pharmaceutical industry is to find a drug that is more effective and with equally few side effects to justify their high prices. Right now they have no competition from vitamins or herbs so they can charge what they want no matter how ineffective or toxic their drug may be.