Prescription vitamin D 23. June 2007 William Davis (32) Niacin:Over-the-counter: $2-5 per monthPrescription: $120 per monthFish oil:Over-the-counter: $3-6 per monthPrescription: $120 per monthVitamin D:Over-the-counter: $2 per monthPrescription: $70 per monthWith vitamin D in particular, the prescription form is vastly inferior to the over-the-counter preparation. This is because the prescription form is ergocalciferol, or vitamin D2, not the effective human form, vitamin D3 or cholecalciferol. When you're exposed to sun, what form of vitamin D is activated in the skin? It's all vitamin D3, no vitamin D2 whatsoever. Vitamin D3 is also far more effective than D2. People taking D3 (as long as it's oil-based) easily obtain healthy levels of vitamin D in the blood. People taking 50,000 units per day of D2 (the recommended quantity) remain miserably deficient, with minor increases in vitamin D blood levels. In short, D2 barely works at all. D3 works easily and effectively.Moreover, D2 is the plant-based form. It is a form not found naturally in humans. D3 is the mammalian form, the same found in humans that exerts all its biologic benefits. Then why is the prescription form of vitamin D2 (brand names Driscol and Calciferol) more expensive? It's the same old pharmaceutical industry scam: Look for something patent protectable, regardless of whether it's superior to the non-patent protectable product, then sell it for exagerated profits. Though it is inferior and the science and clinical experience prove that it's inferior, you can still fool lots of people, including prescribing physicians. So what if you only make $50 or $100 million?Don't fall for it. Prescription doesn't necessarily mean superior. In fact, the prescription form may be significantly inferior, as with vitamin D2. But the pharmaceutical industry carries such power and persuasion, who's going to know?