by Drew_ab » Sat Jan 07, 2023 6:19 pm
I live in a fairly Northern latitude in Canada and for 6 months of year it is simply not possible to obtain sufficient vitamin D from the sun. Thus I supplement with 1000 - 2000 iu's per day for half of the year (a number many consider to be fairly conservative). It isn't a perfect solution, but it is what I have selected. While I know the body stores vitamin D and can hold onto it for a prolonged period of time, my bloodwork has shown that even with generous vitamin D stores at the end of summer, I cannot make it through the winter and maintain a decent vitamin D level. Some people are comfortable with low vitamin D levels over the winter (and argue that it is natural), but I don't arrive at this conclusion as our ancestors haven't lived away from the equator/tropics for a long enough time for evolution to have adapted to this IMO (though clearly in terms of skin pigmentation, some adaptation has taken place). Some day when I am old and retired I will visit warmer climates for a prolonged period each winter where I can get sufficient sun/vitamin D, but until then I am most comfortable with taking a modest supplement. Lastly, I am definitely not comfortable with any form of tanning lamp due to the increase skin cancer risk that may accompany them.
Remember though that most of well-being is tied up in eating well, moving your body, managing stress, having great social connections, good sleep, etc. The amount that adequate vitamin D levels contributes to health is certainly far less than those factors for the overwhelming majority of people. So always focus on the key behaviours that matter most for health and well being. And while Dr. McDougall and Jeff Novick have commented on vitamin D a few times, my impression is that they aren't loosing sleep over this topic. As they always say - "It's the food!" They don't say - "It's the vitamin D!"