As we head into cooler weather, itโs the ideal time to get your vitamin D tested โ whether you live in the north like I do or a warmer climate too.
You may not realize that even people who get adequate sunlight may become vitamin D deficient โ with an impact on their bones.ย Thatโs because vitamin D absorption and utilization differ, sometimes dramatically, from person to person.
Vitamin D needs vary greatly
Here are just a few interesting examples Iโve seen:
- One woman in Connecticut had a vitamin D of level of 33 ng/mL in March โ barely above the acceptable lower limit โ despite taking 6600 IU of vitamin D during winter.ย She increased her intake to 8600 IU for several months to reach the ideal 50 ng/mL level.
- Another northeastern woman tested in August โ when youโd expect her levels to be highest โ was only 35 ng/mL despite taking 2000 IU of vitamin D daily year-round. She needed to add 2000 IU more to reach an optimal level. Contrast this to another client living in Denver, who had 53 ng/mL vitamin D in January when she was only taking 1000 IU daily.
- And then thereโs my own case โ living in central New York, I was using 2800 units of vitamin D during the summer and getting lots of sunshine from my outdoor activities, but I still tested at 35 ng/mL in October.ย If I had not raised my wintertime vitamin D intake substantially to 5,800 IU/day, I wouldโve had a very inadequate level of vitamin D during the winter.
On average, vitamin D levels are expected to increase 10 ng/mL for every additional 1000 IU of vitamin D โ but as you can see, the average doesnโt mean much in real-world situations! Thatโs why itโs crucial to get vitamin D testing to identify where you are starting โ and retest a few weeks later to see if the amount you use is having an impact.
How much Vitamin D should I take?
References:
Boroล, D., Kamiลski, A., Kotrych, D. et al. Polymorphisms of vitamin D3 receptor and its relation to mineral bone density in perimenopausal women. Osteoporos Int (2015) 26: 1045. doi:10.1007/s00198-014-2947-3
Hollis, B. W., Wagner, C. L., Howard, C. R., Ebeling, M., Shary, J. R., Smith, P. G., … & Hulsey, T. C. (2015). Maternal versus infant vitamin D supplementation during lactation: a randomized controlled trial. Pediatrics,136(4), 625-634.
Drincic, Andjela T., et al. “Volumetric dilution, rather than sequestration best explains the low vitamin D status of obesity.” Obesity 20.7 (2012): 1444-1448.
Mayo Clinic. Vitamin D toxicity rare in people who take supplements, researchers report. ScienceDaily, 30 April 2015.
* Information presented here is not intended to cure, diagnose, prevent or treat any health concerns or condition, nor is it to serve as a substitute professional medical care.
