New England, if you thought you were doing yourself a favor by “absorbing” vitamin D through your car window during your morning commute, think again. What you’re really doing is allowing skin-aging UVA rays to penetrate through the glass, while vitamin D-boosting UVB rays can’t penetrate the glass. We’re going to shatter all of the myths about vitamin D, something we Bostonians are severely lacking come winter.
While most people assume simply being in the presence of sunlight is enough to keep their vitamin D levels up, it’s a bit more complex than that, according to Renegade Beauty. When, how, and where you’re in the sun all impact whether or not you’re absorbing vitamin D. According to Boston’s altitude, the 02114 has about 285 days a year where vitamin D can be absorbed naturally from the sun, for 2024, these days are January 31 through November 9, based on the altitude tracking in the dMinder app.
Vitamin D in New England is ‘inadequate’
After November 9, the sun rays will have inadequate UVB, which is the precursor to Vitamin D synthesis in humans. This is all a result of latitudinal changes, aka the earth’s orbit. An NIH study reveals that we Bostonians cannot absorb vitamin D from sunlight from about November through February due to inadequate UVB rays from the sun:
Human skin or [3 alpha-3H]7-dehydrocholesterol exposed to sunlight on cloudless days in Boston (42.2 degrees N) from November through February produced no previtamin D3.
This explains the drop in immunity and the “winter blues” so many Bostonians experience, which is why it’s pivotal to focus on dietary intake of vitamin D in the winter months. Even when UVB does become available in the other 284 days a year, studies show that only certain time windows provide adequate UVB exposure.
Boston, this is a sign to enjoy the last few weeks of blissful sunning until there’s enough vitamin D again in February 2025. Luckily, there are plenty of upcoming winter activities to boost endorphins in lieu of the systemic vitamin D deficiency experienced.