1. Home>
2. Specialties>
3. Dermatology>
4. Summary and Comment

Vitamin D and Death

Low levels of vitamin D spell higher risk for Death.

Vitamin D protects bone, preserves muscle strength, and regulates cell growth and energy metabolism. It also offers some protection against cancer and other disease, but are these effects really important for health and life expectancy? The answer seems to be a resounding yes.

In a prospective cohort study, researchers measured blood levels of 25-hydroxyvitamin D (25VD) and 1,25 dihydroxyvitamin D (1,25VD) in 3258 consecutive patients undergoing coronary angiography. During a mean follow-up interval of 7.7 years, 737 patients (22.6%) died, 463 from cardiovascular disease (CVD). Low serum 25VD and 1,25VD levels were independently associated with all-cause mortality and with CVD. Patients with 25VD levels in the lowest two quartiles (medians, 7.6 and 13.3 ng/mL, respectively) had higher rates of all-cause mortality than did those in the highest quartile (median, 28.4 ng/mL; hazard ratios, 2.08 and 1.53, respectively). The risks for CVD in the two bottom quartiles were even higher (HRs, 2.22 and 1.82, respectively). Similar effects were seen in the lowest quartile of 1,25VD levels. The effects were independent of coronary artery disease, physical activity level, Charlson Comorbidity Index score, variables of mineral metabolism, and cardiac functional class. Low levels were correlated with higher levels of C-reactive protein and interleukin-6.

Comment: This study disturbed the sunphobic in me so much that I increased my daily vitamin D supplementation by 1000 IU. Sunlight stimulates production of vitamin D. Human bodies can make up to 10,000 IU of vitamin D following 30 minutes of skin exposure to summer sunlight. The researchers did not assess sun exposure, although 25VD and 1,25VD levels were higher in participants whose blood was drawn during summer months, as might be expected among these German patients living at latitude 49º.

The results did not show that low vitamin D levels caused increased mortality — only that low levels were associated with increased mortality risk. The authors recommend maintaining serum levels of 25VD of 20 ng/mL or higher. I plan to get mine checked and to monitor my fellow sunphobics among my skin cancer patients.

— Mark V. Dahl, MD

Published in Journal Watch Dermatology August 1, 2008

Citation(s):

Dobnig H et al. Independent association of low serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels with all-cause and cardiovascular mortality. Arch Intern Med 2008 Jun 23; 168:1340.

• Original article (Subscription may be required)
• Medline abstract (Free)