Influence of daily calcium and vitamin D supplementation on parathyroid hormone secretion

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Hi All,

 

This paper suggests that a twice daily dose of both Vit D and calcium is much

better than a once a day dose and may

result in better bone density due to PTH being lower longer and thus possibly

reducing osteoclast (bone eating)

activity.

 

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http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=PubMed & list_uids=1\

1293926 & dopt=Abstract

Gynecol Endocrinol 2001 Feb;15(1):56-62

Influence of daily calcium and vitamin D supplementation on parathyroid hormone

secretion.

Reginster JY, Zegels B, Lejeune E, Micheletti MC, Taquet AN, Albert A.

Bone and Cartilage Research Unit, University of Liege, CHU Centre Ville, 45 Quai

Godefroid Kurth, 4020 Liege, Belgium.

 

Calcium and vitamin D supplementation have been shown to reduce secondary

hyperparathyroidism and play a role in

age-related osteoporosis.

 

In order to define the optimal regimen of calcium and vitamin D supplementation

to produce the maximal inhibition of

parathyroid hormone secretion, we compared the administration of a

calcium-vitamin D supplement as a single morning dose

with the administration of two divided doses at 6-hour intervals.

 

Twelve healthy male volunteers were assigned to three investigational

procedures, which were alternated at weekly

intervals.

 

After a 'blank' control procedure, when they were not exposed to any

supplements, they received one of two

calcium-vitamin D supplement regimens: either two doses of Orocal D3 (500 mg

calcium and 400 IU vitamin D3) with a

6-hour interval between doses, or one water-soluble effervescent powder pack of

Cacit vitamin D3, taken in the morning

(1000 mg calcium and 880 IU vitamin D3).

 

During the three procedures (control and the two calcium-vitamin D

supplementation protocols), veinous blood was drawn

every 60 minutes for up to 9 hours, for serum calcium and parathyroid hormone

measurements.

 

The order of administration of the two calcium and vitamin D supplementation

regimens was allocated by randomization.

 

No significant changes in serum calcium were observed during the study.

 

During the first 6 hours following calcium-vitamin D supplementation, a

statistically significant decrease in serum

parathyroid hormone was observed with both regimens, compared with baseline and

the control procedure.

 

During this first period, no differences were observed between the two treatment

regimens.

 

However, between the 6th and the 9th hour, serum parathyroid hormone levels

remained significantly decreased compared to

baseline with the twice-daily Orocal D3 administration, while they returned to

baseline values with the once-daily Cacit

D3 preparation.

 

During this period, the percentage decrease in serum parathyroid hormone

relative to baseline was significantly greater

with Orocal D3 than Cacit D3 (p = 0.0021).

 

We therefore conclude that the twice-daily administration of 500 mg calcium and

400 IU vitamin D3 at 6-hour intervals

provides a more prolonged decrease in serum parathyroid hormone levels than the

administration of the same total amount

of calcium and vitamin D, as a single morning dose in young healthy.

 

PMID: 11293926 [PubMed - in process]

 

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Good Health & Long Life,

Greg Watson,

http://www.ozemail.com.au/~gowatson

gowatson