70,000 IU of vitamin D had about 30 day half-life – Dec 2012

Pharmacokinetics of a single oral dose of vitamin D3 (70,000 IU) in pregnant and non-pregnant women.

Nutr J. 2012 Dec 27;11(1):114.
Roth DE, Mahmud A, Raqib R, Black RE, Baqui AH.

BACKGROUND: Improvements in antenatal vitamin D status may have maternal-infant health benefits. To inform the design of prenatal vitamin D3 trials, we conducted a pharmacokinetic study of single-dose vitamin D3 supplementation in women of reproductive age.

METHODS:
A single oral vitamin D3 dose (70,000 IU) was administered to 34 non-pregnant and 27 pregnant women (27 to 30 weeks gestation) enrolled in Dhaka, Bangladesh (23[degree sign]N). The primary pharmacokinetic outcome measure was the change in serum 25-hydroxyvitamin D concentration over time, estimated using model-independent pharmacokinetic parameters.

RESULTS:
Baseline mean serum 25-hydroxyvitamin D concentration was 54 nmol/L (95% CI 47, 62) in non-pregnant participants and 39 nmol/L (95% CI 34, 45) in pregnant women. Mean peak rise in serum 25-hydroxyvitamin D concentration above baseline was similar in non-pregnant and pregnant women (28 nmol/L and 32 nmol/L, respectively). However, the rate of rise was slightly slower in pregnant women (i.e., lower 25-hydroxyvitamin D on day 2 and higher 25-hydroxyvitamin D on day 21 versus non-pregnant participants). Overall, average 25-hydroxyvitamin D concentration was 19 nmol/L above baseline during the first month. Supplementation did not induce hypercalcemia, and there were no supplement-related adverse events.

CONCLUSIONS:
The response to a single 70,000 IU dose of vitamin D3 was similar in pregnant and non-pregnant women in Dhaka and consistent with previous studies in non-pregnant adults. These preliminary data support the further investigation of antenatal vitamin D3 regimens involving doses of <=70,000 IU in regions where maternal-infant vitamin D deficiency is common.Trial registration: ClinicalTrials.gov (NCT00938600). PMID: 23268736

Response (from preliminary PDF)

Preliminary PDF is attached at the bottom of this page

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Response to 100,000 IU in another study

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Should have 50,000 IU every week during pregnancy

Everyone should have 50,000 IU every two weeks at a minimum

See also VitaminDWiki

• Overview Loading of vitamin D
• Variety of vitamin D loading dose recommendations in the UK - 2011
• All Megadose vitamin D items 206 items
• Half-life of vitamin D varies
• Overview Pregnancy and vitamin D
• Vitamin D every 14 weeks is not often enough (asthma in this case)– Feb 2019