what-when-how
In Depth Tutorials and Information
conjunction with other therapies, anabolic agents and
new antiresorptive agents that may have a future role in
treatment of OI.
TABLE 56.1
Recommended Daily Vitamin D Intake Based on
Weight for Patients with Osteogenesis Imperfecta*
Age RDA
Weight Recommended**
0-50 years
200 I/U per
day
50lbs/20kg
400-600 I/U
per day
S
UPPLEMENTATION AND O
I
51-70 years
400 I/U per
day
90lbs/40kg
800-1200 I/U
per day
Vitamin D
Vitamin D deficiency is highly prevalent through-
out numerous populations.
14-17
The action of vitamin D
includes its important role in calcium homeostasis, as
well as the prevention of primary hyperparathyroid-
ism and the subsequent activation of osteoclasts.
14,18-20
Vitamin D has beneficial effects on skeletal strength; vita-
min D deficiency is associated with decreased bone min-
eral density in men, women and children.
15,21-25
Vitamin
D deficiency and low bone mineral density are in turn
both associated with abnormalities in bone remodel-
ing, including mineralization that could be particularly
important in OI. Vitamin D insufficiency has been asso-
ciated with decreased bone mineral density in men,
women, and children.
25,26
Additional roles of vitamin D
contributing to fracture prevention include its potential
effects on muscle strength and balance.
27
Recent research
has also suggested that vitamin D, in addition to preven-
tion of primary hyperparathyroidism, may in itself have
some direct action on cortical bone.
21,25,26
Considerable
evidence supports the use of vitamin D replacement
therapy in populations with osteoporosis.
16,18,21,23,24,26,28
Recommended daily intake for vitamin D supplements
has now increased for the general population based on
recent evidence for circulating serum levels required to
prevent primary hyperparathyroidism.
19,29
Guidelines
recently published by the Endocrine Society are intended
to result in serum 25-hydroxyvitamin D (25(OH)D) lev-
els greater than or equal to 30 ng/mL, while the Institute
of Medicine recommends 600 IU/day for ages 1-70 and
800 IU/day for those over 70 with a target serum level of
20 ng/mL or higher.
29,30
Similarly, vitamin D deficiency has been described in
the OI population, with correlates of increased fractures
and decreased bone mineral density.
22,31-33
A clinical
cohort of patients with OI in Baltimore, Maryland, 79%
of type I patients, 84% of type III patients and 100% of
type IV patients had serum 25(OH)D concentrations
under 32 ng/mL.
33
In a pediatric population referred
for clinical concerns of osteopenia or osteoporosis, 80%
of children had 25(OH)D levels under 30 ng/mL, and
among 24 of these patients found to have OI, 19 had lev-
els under 30 ng/mL.
15
Unfortunately, the specific levels
of 25(OH)D that are optimal for patients with OI of any
age are unknown.
Nevertheless, in OI supplementation with vitamin D
and calcium is a common first-line therapy.
6,32
The
70+ years
600 I/U per
day
110lbs/50kg
1000-1500 I/U
per day
1500-2500 I/U
per day
150lbs/70kg+
*
Serum 25(OH)D concentrations should be established with any change in dosing and
monitored during treatment.
**
Shapiro JR, McMahon E, Hollis BW. Correspondance regarding recommendations for
vitamin D intake in osteogenesis imperfecta. April 30, 2012.
guidelines for vitamin D supplementation in the gen-
eral population are standardized by age groups, in part
to take advantage of body size and differences in bone
remodeling needs. Due to considerable variation in body
mass index in the OI population across OI types, set-
ting dose by age may not be as accurate in this popula-
tion. Therefore clinical recommendations for vitamin D
supplementation in patients with OI are based on weight
(Table 56.1).
34
These recommendations provide ranges
observed to result in optimal circulating serum 25(OH)
D levels in this population, and require periodic moni-
toring of serum 25(OH)D, particularly following any
change in dose. In the absence of adequate information
concerning the ideal vitamin D levels in OI, it is probably
reasonable to ensure levels of at least 30 ng/ml.
Calcium and Magnesium
The roles of calcium and magnesium supplementa-
tion in OI remain unclear. Calcium supplementation
is recommended with use of bisphosphonate medica-
tion; however, few studies exist examining calcium,
magnesium and OI. In a small cohort of patients with
type I and type III OI in Brazil, calcium deficiency was
described in 58% of the population following supple-
mentation with recommended daily allowances.
35
The
Institute of Medicine and NIH recommend a daily allow-
ance of 700-1300 g/day and 1000-2000 g/day, respec-
tively, for skeletal health in the general population. These
recommendations are likely reasonable in OI as well but
the most appropriate levels of intake have yet to be clari-
ied.
30
The amounts of calcium in adults with OI may
need to be reduced in the presence of low body size.
Although controversial, recent evidence of increased
cardiovascular risk with calcium supplementation has
introduced new concerns for supplement use in any
population.
30,36
Further research into use of these supple-
ments for OI is needed.
