You take vitamin D every day. You remember your capsule, follow the instructions and expect your next blood test to show an improvement. Then the result comes back: your vitamin D is still low. It can be frustrating—and in a sunny city like Perth, it can seem particularly confusing. But living somewhere with plenty of sunshine does not automatically mean you will have adequate vitamin D. Time spent indoors, clothing, sun-protection habits, darker skin pigmentation, age, body