The most readily available source of vitamin D is the sun’s UVB rays. With cold weather comes more clothing, less outdoor time, and shorter days; possibly resulting in some of our lowest vitamin D levels of the year. Some experts are concerned that the increased use of sun screen is making vitamin D deficiency a year round concern.
Role of vitamin D:
- promotes calcium absorption in the stomach
- maintains serum calcium/phosphate levels
- promotes bone growth/remodeling
- linked with decreased risk of cancer, Crohn’s, depression, type 1 diabetes, MS, autism, and prostate hyperplasia
Vitamin D and your eye:
- associated with increased risk of proliferative diabetic retinopathy
- may contribute to macular degeneration
General guidelines:
- under 1, 400 IU
- between 1-70, 600 IU
- over 70, 800 IU
Those at highest risk of vitamin D deficiency:
- diabetic individuals
- those with macular degeneration
- homebound individuals
- people who have undergone gastric bypass
- those with fat absorption problems
- elderly individuals
If you think you are at risk for vitamin D deficiency, then ask your doctor about having your serum levels tested. It is generally accepted that levels below 30 ng/mL are inadequate and levels above 50 ng/mL are sufficient.
By Dr. Cook, O.D.