Also zinc and copper is found in animal sources. The only non-animal source for vitamin D is UV exposed mushrooms.

Or alternatively you can just go outside for a bit.

You could sunbathe naked in Vancouver for six months a year and not get enough vitamin D.

I had a look, and while that's an exaggeration it's certainly hard to get enough of it in winter. In summer in Calgary it's 600IU per min while in winter it takes 2 hours 42 minutes to get that much. http://purenorth.ca/vitamin-d-your-health/how-much-do-i-need...

That calculator is assuming "midday sun", which doesn't last for very long. (Also, I've been told that 1500 IU/day is what I should aim for.)

That's a lot more than the likes of the Mayo clinic recommend but presumably there is a reason for that. Even if there wasn't, nearly 3 hours outside per day in winter is not that attractive sounding.

My understanding is that 600 IU/day is a "we have lots of evidence that getting less than this is bad" whereas 1500 IU/day is "we know this is completely safe, and there's some evidence that it's better than 600 IU/day". Rather like vitamin C, there's some debate about how much is optimal, but you need to take truly astounding amounts in order to cause adverse effects.

Just wear enough protection, especially if you are in austrailia. Skin cancer is also on the rise.

But not too much protection:

http://www.smh.com.au/lifestyle/diet-and-fitness/the-great-a...