Vitamin D deficiency in homebound elderly persons

Area of Science:

• Gerontology and Nutritional Science
• Biochemistry and Clinical Pathology

Background:

• Vitamin D status is crucial for elderly health, particularly for those with limited sun exposure.
• Homebound elderly and nursing home residents are at higher risk for vitamin D deficiency due to reduced sunlight exposure.

Purpose of the Study:

• To evaluate vitamin D status in homebound elderly, nursing home residents, and healthy ambulatory elderly individuals.
• To identify potential risk factors and biochemical markers associated with vitamin D deficiency in the elderly.

Main Methods:

• A cohort analytic study involving 244 elderly subjects (≥65 years old).
• Included homebound community dwellers (n=116) and nursing home residents, compared with healthy ambulatory controls (n=128).
• Measured serum 25-hydroxyvitamin D (25-OHD) and 1,25-dihydroxyvitamin D (1,25-[OH]2D); assessed parathyroid hormone (PTH), osteocalcin, vitamin D intake, and vitamin D binding protein in subgroups.

Main Results:

• Sunlight-deprived subjects showed mean 25-OHD levels of 30 nmol/L, with 54% of community dwellers and 38% of nursing home residents below 25 nmol/L.
• A significant inverse relationship was found between 25-OHD and PTH levels (r = -0.42, P < .001).
• Vitamin D and calcium intake were below recommended levels in community-dwelling homebound elderly; vitamin D binding protein levels were normal.

Conclusions:

• Homebound elderly individuals are at high risk of vitamin D deficiency, irrespective of vitamin supplementation in the United States.
• Findings underscore the importance of monitoring and addressing vitamin D status in elderly populations with limited mobility and sun exposure.