Vitamin D3 More Effective at Maintaining Vitamin D Blood Levels During Winter
It can be difficult to maintain healthy vitamin D levels in the winter because there is less sunshine and therefore less vitamin D absorption. A recent study suggests that properly maintaining vitamin D levels throughout the winter may depend on the type of vitamin D you're consuming.
Vitamin D2 and D3 are the two biologically inactive forms of vitamin D. When they are introduced to the digestive system they are transformed into 25(OH)D, which is the storage form of vitamin D, or into (1,25(OH)2D), which is the active form.
Researchers at the University of Otago in New Zealand compared vitamin D2 and D3 by mapping the serum levels of 25(OH)D from the summertime peak through the wintertime base. They found that levels were 21 nmol/l lower in participants who received vitamin D2 compared to those who received vitamin D3. Additionally, the D3 group maintained the levels recorded at the beginning of the study period.
For the study, 95 people between the ages of 18 and 50 consumed either a placebo, 1,000 IU of vitamin D2 or 1,000 IU of vitamin D3 daily for 25 weeks, beginning at the end of summer. Serum 25(OH)D levels were measured at baseline and at 4, 8, 13 and 25 weeks.
The study was published in the British Journal of Nutrition on May 21, 2012.
Vitamin D is one of the nutrients absolutely essential to maintaining overall health. Previous studies have shown it to be associated with improved kidney health, reductions in skin cancer, reducing the risk of osteoporosis, improved cardiovascular health, combating diabetes, and improving age related eye degeneration.
Vitamin D can be found in milk, fortified cereals, fish, and eggs. Your body also processes vitamin D from the sun but it becomes harder for our bodies to process vitamin D as we age. This can be a particular problem for people living in the northern hemisphere, where sunlight is scarce for much of the year. A high quality vitamin D3 supplement is always a good option if you feel that you’re not getting enough through diet and sun.