There’s no “safe tan.” In AU/NZ, many people meet vitamin D needs with brief incidental exposure - often minutes - even with sunscreen.
You can maintain healthy vitamin D levels without risking sunburn. Most people only need a few minutes of sun most days, ideally early morning or late afternoon. In summer, 6–8 minutes is often enough; in winter, aim for 30–50 minutes outdoors. People with darker skin may need longer exposure than those with fair skin. Using sunscreen doesn’t appear to reduce vitamin D levels, so keep protecting your skin while enjoying the sun safely.