Hull and East Riding Prescribing Committee
Clinical Guideline on Replacement with High-potency Vitamin D in
patients with vitamin D insufficiency or deficiency
When should vitamin D level be checked?
Test for serum vitamin D (25-hydroxyvitamin D, 25OHD) can be ordered by both
secondary and primary care providers. The conditions where vitamin D levels may be
clinically useful include:
1. Established metabolic bone disease (e.g. primary post-menopausal
osteoporosis, osteoporosis secondary to other medical conditions and/or
drugs, hyperparathyroidism)
2. Suspected osteomalacia: raised ALP, low normal or low serum calcium
3. Secondary prevention (institutionalised elderly) Patients at risk of sarcopenia
and falls
4. Medical conditions predisposing to vitamin D deficiency (e.g. PHPT, coeliac,
Asian pregnant women)
5. Patients receiving highly potent anti-resorptive agents (e.g. intravenous
bisphosphates or denosumab)
At present there is insufficient evidence base for routine testing of vitamin D in
patients with non-specific complaints (e.g. chronic fatigue).
Vitamin D may occasionally be cascaded by clinical staff in biochemistry when
severe deficiency is indicated by other results.
Interpretation of vitamin D results
Vitamin D
Interpretation
< 25 nmol/L
Vitamin D deficiency indicated
25 - 50 nmol/L
Vitamin D insufficiency indicated
50 - 75 nmol/L
Vitamin D status may be suboptimal as it is seasonal
(the lowest levels seen in winter; highest in summer).
For adequacy, vitamin D should be at least 50 nmol/L
at all times. (A result in this range obtained in the
middle of August would be of more concern than if it
was obtained in the middle of January)
75 - 120 nmol/L
Vitamin D sufficient
120 - 200 nmol/L
Vitamin D slightly elevated. Toxicity is usually
associated with levels in excess of 200. Note vitamin
D is seasonal
> 200 nmol/L
Vitamin D consistent with toxicity
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Replacing vitamin D
The decision to replace vitamin D should be tailored according to clinical need. Not
every patient with low vitamin D levels needs replacement.
Theoretically, 100 IU of vitamin D (colecalciferol or ergocalciferol), increases 25OHD
by 2.5nmol/L. For example, 2 tablets of Calceos (800IU of colecalciferol) could be
expected to increase 25OHD by 20nmol/L. However, adherence to calcium and
vitamin D compounds is poor. In clinical practice, the observed rise in 25OHD is often
much lower than predicted. High potency vitamin D compounds are often needed to
achieve clinically desired levels.
Replacement choices have become more limited with the recent national shortage of
ergocalciferol. Colecalciferol is an alternative with comparable biological potency and
longer half-life.The only licensed high-potency colecalciferol preparation is ‘FultiumD3’. This is the form of colecalciferol used by Hull and East Yorkshire Hospitals NHS
Trust.
The following algorithm has been proposed for use within the Hull and East Riding
health community. The advice is in line with national practice, utilising available highpotency vitamin D preparations.1
ALLERGY WARNING
Please note some brands of colecalciferol (including Fultium D3, Dekristol –
currently used by Hull and East Yorkshire Acute Trust) contain peanut oil and
is contraindicated in patients with allergy to peanut and soya oil.
Prescribers and pharmacist should check food allergy before supply is made.
Replacement regime for vitamin D deficiency (<25 nmol/L)
Starting dose and monitoring arrangements are summarised in Table
Pre-treatment 25OHD level
Regime
<15 nmol/L


15 – 25 nmol/L


Colecalciferol (Fultium D3) 3200 IU
(4 capsules taken as a single daily dose) for 12
weeks.
Repeat as necessary depending on 25OHD
level at end of course.
Colecalciferol 3200 IU
(4 caps) daily for 8 -12 weeks.
Repeat as necessary depending on 25OHD
level at end of course.
1. Ensure test is recent (within 6 weeks). Repeat test especially if lower levels were
tested in winter.
2. Check biochemical profile (BCP). If calcium is high (>2.6 mmol/L) or high-normal
(2.5-2.6 mmol/L) despite vitamin D deficiency, there may be co-existing primary
1
Pearce SHS, Cheetham TD. Diagnosis and management of vitamin D deficiency. BMJ
2010;340:142.
Page 2 of 5
hyperparathyroidism (PHPT). Consider referral to secondary care. If co-existing
PHPT is suspected, consider referral to secondary care.
3. Check BCP at week 1, 4 and 8. The purpose is to avoid hypercalcaemia and
acute kidney injury that occur (rarely) in association with vitamin D correction.
4. Repeat vitamin D at completion of treatment.
5. If the 25OHD levels are satisfactory (at least 50 nmol/L) maintenance should be
with Calcium/Vitamin D preparations (e.g. Calceos 2 tablets daily).
6. If the levels remain less than 25nmol/L, adherence should be ascertained and the
course may be repeated.
7. If the levels are between 25-50nmol/L, follow the replacement regime below.
Replacement regime for vitamin D insufficiency (25-50 nmol/L)
Pre-treatment 25OHD level
Regime
40 - 49 nmol/L


26 - 39 nmol/L


Use standard calcium/vitamin D preparations to
achieve levels.
Consider colecalciferol 1600 IU (2 capsules of
800 IU taken as a single daily dose) for 8
weeks
Colecalciferol 1600 IU
(2 caps) daily – for 8 -12 weeks
Repeat as necessary depending on 25OHD
level at end of course.
1. Ensure test is recent (within 6 weeks). Repeat test especially if lower levels were
in winter.
2. Marginally low 25OHD levels may resolve in spring/summer. Note that the
probability of low vitamin D recurring in autumn/winter is high. Consider repeating
25OHD just before winter.
3. Routine monitoring of BCP is not mandatory.
4. Monitoring is recommended in some patients covered (see below). Check BCP at
weeks 1, 4 and 8.
5. Repeat vitamin D at completion of treatment.
6. If the vitamin D levels are satisfactory (at least 50 nmol/L) maintenance should be
with Calcium/Vitamin D preparations (e.g. Calceos 2 tablets daily).
7. If the levels remain less than 50 nmol/L, adherence should be ascertained and
the course may be repeated.
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Monitoring
1. Monitoring is the responsibility of the prescriber.
2. Where colecalciferol is prescribed by the specialist and it is impracticable for the
patient to return to secondary care for phlebotomy, Lab 1A form(s) should be
completed by the prescribing specialist in order for phlebotomy to be arranged by
GP surgery.
3. Patients who should receive routine monitoring is outlined in table below.
Patient category
Notes
Known primary hyperparathyroidism (PHPT)
 Patients with known PHPT with associated
vitamin D deficiency.
 Vitamin D deficiency coexists with, is
exacerbated by, and itself exacerbates
adenomatous PHPT.
 Correction may be desirable (a) to avoid
post-operative hypocalcaemia and (b) to
minimise skeletal complications of PHPT.


Monitoring is mandatory.
Treatment should be initiated
by secondary care specialist.
Possible/masked PHPT
More common in older women. Suspect if:
 Calcium high normal (2.5 – 2.6 mmol/L) or
 Previous high calcium (>2.6 mmol/L) –
check prior results, or
 Low phosphate with high normal/high
calcium

Monitor BCP at weeks 1, 2, 4,
8 and 12.
Consider starting at a lower
dose than indicated for
correction.
Kidney disease/renal impairment
 CKD Stage 3B – eGFR 30 –
45ml/min/1.73m2
 Chronic volume depletion – e.g. long-term
diuretic therapy
 Structural renal disease

Note this guidance does not
apply to those with CKD 4 or 5
in whom vitamin D
replacement (where indicated)
should be guided by
secondary care.
Very low vitamin D

Over correction infrequently
occurs with high doses of
colecalciferol used.

Caution
1. Incidental finding: A significant proportion of people in the general population,
and a larger percentage of hospital in-patients, will have low vitamin D levels. At
present, there is no recognised public health indication for routine replacement of
otherwise asymptomatic healthy individuals in whom low vitamin D levels were
incidentally detected.
2. Activated vitamin D: Some patients, esp. those known to secondary care
services, may be taking activated vitamin D in the form of calcitriol or alfacalcidol.
The present guidelines do not apply to those patients. Low 25OHD levels in those
patients should not be corrected except with advice from the relevant secondary
care specialist.
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Renal disease: This guidance does not apply to patients with chronic kidney disease
who have estimated GFR 30/ml/min/1.73m2 or worse (e.g. CKD Stage 4 or worse).
Flowchart summarising the treatment algorithm for correction of vitamin D
insufficiency or deficiency with colecalciferol
Vitamin D status assessed
Ensure results recent.
Check BCP
25OHD
<25 nmol/L
If 25OHD <15
Colecalciferol
3200IU
(4 caps)
for 12 weeks
If 25OHD 15-25
Colecalciferol
3200IU
(4 caps) for 8 12 weeks
Check BCP at weeks 1, 2, 4, 8 and 12.
Check 25OHD at completion of course
25OHD
25-50 nmol/L
If 25OHD 26-39
Colecalciferol
1600IU
(2 caps) for 8 12 weeks
If 25OHD ≥ 40
Consider
standard Ca/D.
Or colecalciferol
1600IU (2 caps)
for 8 weeks
Routine monitoring only in selected
group of patients (see text).
Check 25OHD on completion of course.
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Ca >
2.5
Consider overt or
masked PHPT
25OHD
>50 nmol/L
Correction may
not be tested at
this stage.
Consider retesting in winter