All-Source Basal Vitamin D Inputs Are Greater Than Previously Thought and Cutaneous Inputs Are Smaller.
J Nutr. 2013 Mar 20.
Heaney RP, Armas LA, French C.
Creighton University, Omaha, NE.
The magnitude of vitamin D inputs in individuals not taking supplements is unknown; however, there is a great deal of information on quantitative response to varying supplement doses.
We reanalyzed individual 25-hydroxyvitamin D [25(OH)D] concentration data from 8 studies involving cholecalciferol supplementation (total sample size = 3000). We extrapolated individual study dose-response curves to zero concentration values for serum 25(OH)D by using both linear and curvilinear approaches and measured seasonal oscillation in the serum 25(OH)D concentration. The total basal input (food plus solar) was calculated to range from a low of 778 iu/d in patients with end-stage renal disease to a high of 2667 iu/d in healthy Caucasian adults. Consistent with expectations, obese individuals had lower baseline, unsupplemented 25(OH)D concentrations and a smaller response to supplements. Similarly, African Americans had both lower baseline concentrations and lower calculated basal, all-source inputs.
Seasonal oscillation in 4 studies ranged from 5.20 to 11.4 nmol/L, reflecting a mean cutaneous synthesis of cholecalciferol ranging from 209 to 651 iu/d at the summer peak.
We conclude that:
- 1) all-source, basal vitamin D inputs are approximately an order of magnitude higher than can be explained by traditional food sources;
- 2) cutaneous, solar input in these cohorts accounts for only 10-25% of unsupplemented input at the summer peak; and
- 3) the remainder must come from undocumented food sources, possibly in part as preformed 25(OH)D.
Lots more in the publication, but publisher does not permit access by people who do not pay.
The Dr. Heaney has provided an excellent chart which was used in the publication.
dashed lines and text added by VitaminDWiki
- Overview Vitamin D Dose-Response which includes
Need 14,100 IU/d to get 97.5% of the population above 50 ng/ml
Half of seniors did not respond to 1600 IU of vitamin D daily for a year
- Is 50 ng of vitamin D too high, just right, or not enough which includes the following notional graph
- How to 2X the response to vitamin D supplements
- Dose response equation square root of IU
- Vitamin D levels vs weight – RCT Dec 2012
- European Osteo group recommends 20-50 ng of vitamin D – Jan 2013
- Even taking as much as 4200 IU vitamin D 43 percent had less than 30 ng in blood – RCT Jan 2013
- Vitamin D Insufficiency is less than 32 or 40 ng – Heaney 2012 same author as this paper
- All items with the word Heaney in VitaminDWiki 340 as of Nov 2013
- Vitamin D supplementation - Grassroots Jan 2013 which has the following chart
Same dose of vitamin D for everyone is virtually impossible - Dec 2015
Dose/response from 36 studies
solid line = mean response (50% above, 50% below)
Lower dashed line = 97.5% will have achieved the level
To get 80% of people to 40 ng level
Short url = http://bit.ly/16TuWp5