SAVED
File name
.JPG
File alt. text
Image should be
px wide x
px tall.
Select Image
Select Image
L
O
G
I
N
EXISTING USERS
NEW USERS
password:
Forgotten your password?
password:
LOG IN
REGISTER
The Gastroenterology Training Handbook
For Specialist Registrars
HOME
OESOPHAGUS
•Gastro Oesophageal Reflux Disease
•Oesophageal Cancer
•Oesophageal Dysmotility
•Benign Oesophageal Lesions
•Miscellaneous
•Dysphagia
STOMACH
•Obesity Surgery
•Clinical Presentations of Gastric Conditions
•Gastric Cancer
•Gastric Polyps and Masses
•Peptic Ulcer Disease
•Gastritis and Gastropathy
•Miscellaneous
SMALL BOWEL
•Coeliac Disease
•Small Bowel Infections
•Small Bowel Masses
•Miscellaneous
COLON
•Colorectal and Anal Cancer
•Diagnostic Pathways for Colonic Disease
•Colonic Vascular Disorders
•Anal Diseases
•Various Colitides
•Colonic Motility Disorders
•Miscellaneous
•Colonic Infection
LIVER
•Alcohol
•Liver Failure
•Miscellaneous
•Ascites
•Bilirubin Metabolism
•Vascular Problems
•Clinical Presentations
•Liver Masses
•Hepatitis B
•Hepatitis C
•Autoimmune Conditions
•Metabolic Conditions
•Treatments
•Various Viruses
•Hepatopulmonary Disorders
•Liver Imaging
BILIARY
•Gallstone Disease
•Biliary Cancers
•Biliary Parasites
•Miscellaneous
NUTRITION
•Nutrition Therapy
•Minerals
•Proteins, Fats and Sugars
•Vitamins
•Clinical Conditions and Nutrition
PANCREAS
•Pancreatitis
•Pancreatic Masses and Cysts
•Pancreatic Cancers
•Other
IBD
•Epidemiology
•IBD Diagnosis
•Extra Intestinal Manifestations
•Surgery
•Treatment
MISCELLANEOUS
•Bleeding
•Rheumatological Disease
•Infection
•Vascular Lesions
•Other
home -
Nutrition -
Vitamins -
Vitamin D
search
Ask a question in the forum
Written by Dr Sebastian Zeki
MCQs for this page
Vitamin D
View large version
Embed image
paste this code into your webpage / blog to share.
Protein
D
Micelles
D
Pancreatic
enzymes
Bile
acids
Absorption
into entero
-
cyte in distal
small bowel
Packaged into
chylomicrons
25-
vitamin-D
hydroxylase
25-hydroxy-
vitamin-D
(25OHD)
1,25-dihydroxy-
vitamin D (1,25(OH)2-
vitamin D) This is the
physiologically active
form
Vitamin D
PTH
+
Enhances intestinal
absorption of
calcium
Bone
Oestrogen
Placental growth hormone
Prolactin
May also regulate vitamin D
metabolism
Excess
Hypercalcaemia (usually if >60,000U/ day).
Maximum tolerated daily dose is <2000IU.
Glucocorticoids, when
used chronically in high
doses, inhibit the
intestinal vitamin D
dependent calcium
absorption and therefore
cause osteomalacia
Causes of Deficiency
Deficiency
Early in hypovitaminosis D, hypophos
-
phatemia is more marked than hypocalcae
-
mia.
With persistent hypovitaminosis D,
hypocalcemia causes a secondary hyperpar
-
athyroidism that leads to phosphaturia,
demineralization of bones, and, without
treatment, to
osteomalacia
in adults and
rickets in children.
Liver damage (unable
to hydroxylate
Kidney
damage
End organ
insensitivity to vit D
Action of Vitamin D
Requirements of
vitamin D —
RDA: 800 IU/ d
If low give 50,000 units
vitamin D2
(ergocalciferol 2-3x/wk
until normal levels
25-OH vitamin D is
best serum measure-
need minimum level of
30 ng/ml (75 nmol/L)
Serum PTH is inversely
related to 25-OH
vitamin D
Provitamin D
Vitamin D3
Sunlight
bound to
Vitamin D binding
proteins (DBP)
Blood
Skin
Diet
Fortified milk, bread and cereal
Fatty fish
Cod-liver oil
Eggs.
Vitamin D
Sources
Mechanism of absorption
Investigation and treatment of Vitamin D Deficiency
Vitamin D symptoms present?
-Widespread bone pain/ tenderness or myalgia
Proximal muscle weakness
Tenderness over pseudofractures
Insufficiency fractures
Does the patient have >1 risk factor for vitamin D deficiency?
Black/ ethnic minority
Elderly and housebound
Habitual skin covering
Vegan/ vegetarian
Liver/ renal disease
Malabsorption
Anticonvulsants/
cholestyramine/
rifampicin/
anti-retrovirals
Vitmain D tests: 25(OH)D,Ca2+,PTH,ALP,PO4
Deficiency <25nmol/L
1st line: Colecalciferol 20,000U capsule: Take 3 caps ow for
12 weeks
2nd line: Colecalciferol 300,000U IM injection.One
immediately then repeat at 12 weeks
3rd line: 300,000U in 100ml colecalciferol liquid: Take 50ml
od for 2 days
Insufficiency 25-50nmol/L
Colecalciferol 1,000U tablet:
Take 1-2 taletsod for 12 weeks
Sufficient >50nmol/L
Lifestyle and dietary advice
Repeat levels at 12 weeks.
Monitor patient every 12 months
Consider maintenance if ongoing risk
1st line: cacium carbonate 1.5g & colecalciferol 400U chewable tablet: 1 tablet bd
2nd line: Colecalciferol 1,000U tablet: od (only if adequate ca intale or at risk of hypercalcaemia)
AND
Treatment based on serum 25-OH D level
If still insufficient
then refer for
specialist advice
Related Stories
•
•
•
•
•