A High Prevalence of Vitamin D Inadequacy in aMinimal Trauma Fracture Population

A High Prevalence of Vitamin D Inadequacy in aMinimal Trauma Fracture Population

C. Simonelli,1 JA Morancey,1 L Swanson,1 KK Kileen,1 KA Grimm,1T Weiss,2 Y-T Chen2

1HealthEast Medical Research Institute, St. Paul, MN, USA, 2Merck & Co., West Point, PA, USA

BACKGROUND

To determine the prevalence of vitamin D inadequacy, as determined by serum level of 25 hydroxyvitamin D [25 (OH)D], in a population of adults hospitalized with non-traumatic fractures.

Study population: Patients age 50 years and older who were hospitalized for a fracture between 8/1/01 and 1/31/02 in a single health system in Minnesota– Patients were excluded if they had a high impact trauma, metastatic cancer diagnosis, or were non-communicative

or failed to consent Data Collection on admission

– Demographics, medical and lifestyle information by chart review or patient self-report• Gender, age, ethnicity, admitting fracture site, BMD testing• Vitamin D and calcium supplementation, multivitamin intake, exercise, diet• Osteoporosis medication use: none, estrogen, alendronate, risedronate, etidronate, raloxifene, calcitonin

– Laboratory testing within 48 hours of hospitalization• Vitamin D, parathyroid hormone, creatinine, calcium, albumin, alkaline phosphatase, protein electrophoresis

OBJECTIVE

METHODS

Results may not be applicable to other populations:– All patients from a single healthcare organization in the

Midwest at latitude of 42 degrees– Small sample size– Older population– Lack of ethnic minorities

Variation in serum 25(OH)D assays may confound the diagnosis of vitamin D inadequacy across studies1

Persistence and compliance of vitamin D use can not be examined due to the lack of information on the frequency and duration of vitamin D supplementation

1. Binkley, et al. JCEM 2004;89:3152-7

97% of hospitalized fracture patients had serum vitamin D [25(OH)D] levels < 30 ng/mL

Half had little or no vitamin D supplementation Serum vitamin D levels did not differ by age, sex, or

use of osteoporosis medications on admission Patients taking at least 400 IU of vitamin D daily in

supplement form had higher mean serum vitamin D levels than those that did not

Nearly all patients in this study hospitalized for fracture had serum vitamin 25(OH)D inadequacy, even those who were considered taking moderate(> 400 IU) daily supplementation of vitamin 25(OH)D.

Significant opportunity exists to ensure adequate and persistent vitamin 25(OH)D intake in patients at risk for fracture.

CONCLUSION

SUMMARY

POSSIBLE LIMITATIONS

Serum Vitamin D Assessment Blood specimens collected during hospitalization within 48

hours of admission Serum 25-hydroxyvitamin D [25 (OH)D] levels were

performed using Diasorin 25-hydroxyvitamin D radioimmunoassay kit (RAI)

– With reference sub range of 8-30 ng/mL determined by wintertime in Rochester, MN

Blood specimens were analyzed by Mayo Clinic, Rochester, MN

Results of 25(OH)D levels available for 78 of 82 patients identified for the study

Various cut points of serum 25(OH)D were used to define prevalence of vitamin D inadequacy:(< 9 ng/mL,< 15 ng/mL, < 25 ng/mL, < 30 ng/mL)

Vitamin D, Calcium, andMultivitamin Supplementation

Vitamin D, calcium, and multivitamin use on admission was collected by patient self-report:

- Vitamin D (IU/day): none, 200, 400, 800

- Calcium (mg/day): none, < 500, 501-750,751-1000

- Multivitamin use: no, yes

Daily dose of vitamin D was calculated by adding the reported dosage of vitamin D use and 400 IU/day if patient reported taking multivitamin

Daily Vitamin D Supplementation & Multivitamin Intake on Admission (n=78)

N (%)Vitamin D only 14 (18%)

200 IU 7 (9%) 400 IU 7 (9%)

Multivitamin only* 36 (46%)Vitamin D 400 IU 39 (50%)and/or multivitamin*

*Assumes 400 IU vitamin D in multivitamin

Mean Vitamin D [25(OH)D]Mean (SD)

ng/mLOverall 14.2 (6.6)Sex

Women 14.1 (6.7)Men 14.3 (6.4)

Age< 80 16.6 (7.4)80+ 13.9 (6.1)

Osteoporosis medication usageYes 15.3 (3.9)No 14.0 (6.9)

Vitamin D supplementation 400 IU/day*Yes 16.4 (6.9)No 11.9 (5.5)

Mean 25(OH)D levels not statistically different by gender, age, or osteoporosis medication use*p=0.002

RESULTS

Characteristics of Study Populationon Admission N (%)

Female 61 (78%)Caucasian 77 (99%)Age 50-79 29 (37%)Age 80-99 49 (63%)Hip Fracture 64 (82%)Osteoporosis Medication 10 (12%)Calcium supplementation 27 (35%) 500 mg/day

*N=78

Cutoff points for Serum-25(OH)D (ng/mL)

Prevalence of Vitamin D Inadequacy by Vitamin D Supplementation Status

* ≥ 400 IU/day including vitamin D obtained by multivitamin** 35 patients reported no daily vitamin D or multivitamin supplementation, while 4 reported vitamin D supplementation of ≤ 200 IU/day but no multivitamin intake

Cutoff points for Serum-25(OH)D (ng/mL)

Pe

rce

nt

0

20

40

60

80

100

<9 <15 <20 <25 <30

Vit D ≥ 400 IU (n=39)*Vit D < 400 IU (n=39)**

Cutoff points for Serum-25(OH)D (ng/mL)

Pe

rce

nt

Age 50-79 (n=29)Age 80+ (n=49)

0

20

40

60

80

100

<9 <15 <20 <25 <30N=78

Prevalence of Vitamin D Inadequacy

Prevalence of Vitamin D Inadequacyby Age Group

Pe

rce

nt

20.5

52.5

80.8

96.2 97.4

0102030405060708090

100

<9 <15 <20 <25 <30

Vitamin D is essential for the management of osteoporosis to prevent fractures. Vitamin D plays a critical role in:

– Ensuring dietary calcium absorption– Normal mineralization of bone– Prevention of osteomalacia and secondary hyperparathyroidism

The ideal serum vitamin D level is unknown; however > 30 ng/mL is considered optimal1

The prevalence of vitamin D inadequacy is not known in patients hospitalized for fractures – a population that is at very high risk for subsequent fractures

1. Heaney, et al. J Am Nutr 2003;22:142-146