Self-prescribed high-dose vitamin D3: effects on biochemical parameters in two men

Ann Clin Biochem 2008;45:106-110
doi:10.1258/acb.2007.007074
© 2008 Association for Clinical Biochemistry

 

This Article
Right arrow
Figures Only
Right arrow
Full Text
Right arrow

Full Text (PDF)

Right arrow
Alert me when this article is cited
Right arrow
Alert me if a correction is posted
Services
Right arrow
Email this article to a friend
Right arrow

Similar articles in this journal

Right arrow
Similar articles in PubMed
Right arrow
Alert me to new issues of the journal
Right arrow
Download to citation manager
Right arrow
Citing Articles
Right arrow
Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow
Articles by Kimball, S.
Right arrow
Articles by Vieth, R.
Right arrow Search for Related Content
PubMed
Right arrow
PubMed Citation
Social Bookmarking

What’s this?

Case Report


Samantha Kimball 1 2  and
Reinhold Vieth 1 2 3


1 Department of Nutritional Sciences, University of Toronto, Toronto, Canada M5S 3E2;
2 Department of Pathology and Laboratory Medicine, Mt Sinai Hospital, Toronto, Canada M5G 1X5;
3 Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, Canada M5S 3E2


Corresponding author: Dr Samantha Kimball, Department of Pathology and Laboratory Medicine, Mt Sinai Hospital, Toronto, Canada M5T 3L9. Email: samantha.kimball{at}utoronto.ca

The lowest observed adverse effect level for vitamin D, said to cause hypercalcaemia in normal adults, is officially 95 µg/day. Serum 25-hydroxyvitamin D (25[OH]D) concentrations associated with hypervitaminosis D remain undefined. Reported 25(OH)D concentrations resulting from prolonged excessive vitamin D3 intakes have exceeded 700 nmol/L. We report self-prescribed high dose of vitamin D3 over 5–6 years by two men. Subject 1 had been taking 100 µg/day for 3 years followed by 3 years of 200 µg/day. Serum 25(OH)D concentrations averaged 130 nmol/L while taking 100 µg/day of vitamin D3. While taking 200 µg/day of vitamin D3, mean serum 25(OH)D concentrations were 260 nmol/L with no hypercalcaemia or hypercalcuria over the 6 years of vitamin D3 intake. Subject 2 was a 39-year-old man diagnosed with multiple sclerosis. He initiated his own dose-escalation schedule. His vitamin D3 intake increased from 200 to 2200 µg/day over 4 years. The first evidence of a potential adverse effect was that urinary calcium:creatinine ratios showed an increasing trend, which preceded serum calcium concentrations above the reference range (2.2–2.6 mmol/L). His serum 25(OH)D concentration was 1126 nmol/L when total serum calcium reached 2.63 mmol/L. He stopped vitamin D3 supplementation at this point. Two months later, all biochemistry values were within reference ranges; serum 25(OH)D concentrations fell by about one-half, to 656 nmol/L. These results help to clarify the human response to higher intakes of vitamin D3. Close monitoring of biochemicalresponses confirmed that an increase in urinary calcium:creatinineratio precedes hypercalcaemia as serum 25(OH)D concentrationsrise.


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What’s this?






This article has been cited by other articles:

Home page BMJHome page

S. H. Pearce and T. D Cheetham
Diagnosis and management of vitamin D deficiency
BMJ,

January 11, 2010;

340(jan11_1):

b5664 – b5664.

[Full Text]



V. Mocanu, P. A Stitt, A. R. Costan, O. Voroniuc, E. Zbranca, V. Luca, and R. Vieth
Long-term effects of giving nursing home residents bread fortified with 125 {micro}g (5000 IU) vitamin D3 per daily serving
Am. J. Clinical Nutrition,

April 1, 2009;

89(4):

1132 – 1137.

[Abstract]
[Full Text]
[PDF]


Home page Ann Clin BiochemHome page

S J Costelloe, E Woolman, S Rainbow, L Stratiotis, G O’Garro, S Whiting, and M Thomas
Is high-throughput measurement of 25-hydroxyvitamin D3 without 25-hydroxyvitamin D2 appropriate for routine clinical use?
Ann Clin Biochem,

January 1, 2009;

46(1):

86 – 87.

[Full Text]
[PDF]