Response of Vitamin D Concentration to Vitamin D3 Administration in Older Adults without Sun Exposure: A Randomized Double-Blind Trial.
J Am Geriatr Soc. 2016 Jan;64(1):65-72. doi: 10.1111/jgs.13774.
Schwartz JB1,2,3, Kane L1, Bikle D2,4.
1 Jewish Home of San Francisco, San Francisco, California.
2 Department of Medicine, University of California at San Francisco, San Francisco, California.
3 Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, California.
4 Department of Dermatology, University of California at San Francisco, San Francisco, California.
- Suspect that the much higher response to 50,000 IU of vitamin D is due to taking blood samples too soon after taking the vitamin D – during the peak response which persists for ~3 days after a high dose.
See also VitaminDWiki
- How often might 50000 IU vitamin D be taken - results of clinical trials
- Is 50 ng of vitamin D too high, just right, or not enough
- 10 reasons why seniors need more vitamin D has the following
- Senior skin produces 3X less Vitamin D for the same sun intensity
- Seniors have fewer vitamin D receptors as they age
(The effect of low Vitamin D receptor genes does not show up on vitamin D test results)
- Seniors are indoors more than when when they were younger
not as agile, weaker muscles; frail, no longer enjoy hot temperatures
(if outside, stay in the shade), however, seniors might start outdoor activities like gardening, biking, etc.
- Seniors wear more clothing outdoors than when younger
fear skin cancer/wrinkles, sometimes avoid bright light after cataract surgery
- Seniors often take various drugs which reduce vitamin D (some would not show up on vitamin D test) statins, chemotherapy, anti-depressants, blood pressure, beta-blockers, etc
- Seniors often have one or more diseases which consume vitamin D ( osteoporosis, diabetes, MS, ...)
- Seniors generally put on weight at they age - and a heavier body requires more vitamin D
- Seniors often (40%) have fatty livers – which do not process vitamin D as well
- Seniors not have as much Magnesium needed to use vitamin D
(would not show up on vitamin D test)
- Seniors with poorly functioning kidneys do not process vitamin D as well
(would not show up on vitamin D test) 2009 full text online Also PDF 2009
- Vitamin D is not as bioavailable in senior digestive systems (Stomach acid or intestines?)
- Category Seniors and Vitamin D
Overview Vitamin D Dose-Response has many charts, including the following
OBJECTIVES: To determine the dose-response relationship between 25-hydroxyvitamin D (25(OH)D) and supplemental vitamin D3 in elderly nursing home residents.
DESIGN: Randomized double-blind investigation.
SETTING: Nursing home.
PARTICIPANTS: Of 81 women (n=51) and men (n=30) (mean age 87.4±8) enrolled, 72 completed the study.
INTERVENTION: Sixteen weeks of oral vitamin D3 at 800, 2,000, or 4,000 IU/d or 50,000 IU/wk.
MEASUREMENTS: The main outcome was 25(OH)D concentrations (tandem mass spectrometry) after 16 weeks. Free 25(OH)D and intact parathyroid hormone (iPTH) were also analyzed. Safety monitoring of calcium and estimated glomerular filtration rate was performed, and adherence and clinical status were measured.
RESULTS: 25(OH)D concentrations increased with dose (P<.001) and were higher with 50,000 IU/wk (P<.001) than other doses and with 4,000 IU/d than 800 or 2,000 IU/d, but 800 IU and 2,000 IU/d did not differ. One subject receiving 800 IU/d had concentrations less than 20 ng/mL. All subjects receiving more than 2000 IU/d had concentrations of 20 ng/mL and greater. Free 25(OH)D concentrations rose with total 25(OH) vitamin D. Total and free 25(OH)D were related to calcium concentrations; only free 25(OH)D was related to iPTH.
CONCLUSION: 25(OH)D increased linearly with 800 to 4,000 IU/d and 50,000 IU/wk of vitamin D3, without a ceiling effect. Data suggest that some elderly adults will require more than 800 IU/d of vitamin D3 to ensure adequate vitamin D levels. Changes in 25(OH)D with vitamin D3 were related to starting concentrations (greatest with the lowest concentrations and unchanged with 800 and 2,000 IU/d if 20-40 ng/mL). Relationships between serum calcium and iPTH and free 25(OH)D suggest the potential for free 25(OH)D in defining optimal 25(OH)D concentrations.