> At a checkup a few years ago, a doctor told me I was deficient in vitamin D. But he wouldn’t write me a prescription for supplements, simply because, as he put it, everyone in the UK is deficient. Putting the entire population on vitamin D supplements would be too expensive for the country’s national health service, he told me.

Ugh. It's amazing how incompetent medical systems are. I was also deficient in vitamin D and my doctor wrote a prescription. When I did the math, the cost was something like >$.10 per 1000IU. But if I bought the vitamins from a normal store, I would pay <$.01 per 1000IU. Since a person lacking sunlight only needs 1000IU, the price for giving everyone in the UK Vitamin D would be <$700k/day. And probably much less since most people won't need this high of a dose and bulk quantities would be cheaper.

For healthy people, taking extra vitamins is pointless, but giving them to people who are deficient in vitamins is one of the cheapest health interventions for the benefits.

PSA: if you're feeling off, make sure your doctor checks your various vitamin levels and see if cheap OTC vitamins help.

I found that taking a specific brand of Vitamin D (the Genestra D-mulsion in particular) right before bed was guaranteed to give me vivid dreams. I've had half a dozen friends try it, with every single one reporting similar results.

It’s interesting that his doctor wouldn’t prescribe a vitamin D supplement because it would supposedly be too expensive for the health care system. Fortunately, vitamin D supplements are generally inexpensive to buy. I doubt I’d ever get a prescription for one, they’d probably just tell me to pick some up at the pharmacy downstairs.

Good article, but it does not cover toxicity; you can take too much vitamin D and this has very negative affects. Usually a multivitamin is enough for supplementing; taking extra is where you can run into issues; consult your Doctor.