Can Sunshine During the Summer Months Provide Enough Vitamin D?
To start this discussion, it is important to remember that these days many of us go from our house, to our car, to our office building, back to our car, back to our house; and when we are in the sun, we are wearing sunscreen. You might not get as much sun as you think. For many years, people thought that extra amounts of vitamin D made by the sun during the summer could be stored in the body and used during the winter. Probably due to modern lifestyles and the use of sunscreen, we are now finding that most people, whether vegan or not, do not sustain optimal levels throughout the winter, and many don’t even sustain them through the summer – especially in non-equatorial regions of the world. A 2003 study by Heaney et al.7 indicates that male adults in good health, living in Nebraska, and starting with a healthy supply of vitamin D still need about 12 mcg (480 IU) per day of vitamin D during the winter to keep their stores from diminishing. And what may be even more important is how PTH
