<s>[INST] Can I get all the vitamin D I need from sunshine?  [/INST] Large amounts of Vitamin D3 are made in your skin when you expose your entire body to summer sun, so it is technically possible that sun exposure will produce all you need. However, the average person does not spend enough time outdoors every single day so a quality D3 supplement is important. As far as sun exposure goes, there is no magical formula to tell you how long one should be outside each day because there are many factors that play into just how much exposure is necessary. It could be just 15 minutes of exposure for a fair skinned person, but a couple of hours for a more dark skinned person. The amount of vitamin D you get from exposing your bare skin to the sun depends on:

– The time of day – Your skin produces more vitamin D if you expose it during the middle of the day
– Your geographic location – the closer you are to the equator, the more intense the exposure is to the sun, so it would be quicker to produce vitamin D.
– The color of your skin – pale skin makes vitamin D quicker than dark skin
– The amount of skin you expose – the more skin that is exposed, the more vitamin D your body will produce.
– Age – as we age, our skin has a harder time producing vitamin D

 Source: OSC - ORTHO. Link: https://www.osc-ortho.com/frequently-asked-questions-about-osteoporosis/. Field: Rheumatology. Disease: Ostoeporosis </s>