3

votes

How long would it take to become Vit D deficient?

Answered on September 12, 2014
Created June 19, 2013 at 7:48 PM

Or, how long do healthy stocks of Vit D 'last' in a body? Quite a while I imagine but just wondered if there were any studies.

Medium avatar

(78)

on July 17, 2014
at 04:08 PM

Have you ever considered that maybe you were lacking something that helps with D absorption, like magnesium or Vit A? It's just so hard to figure out the right balance!

Medium avatar

(78)

on July 17, 2014
at 04:07 PM

oh my gosh, so your levels dropped that much even though you were getting a lot of sun exposure? That scares me! An hour is a long time and I thought very suitable for Vitamin D production!

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 06:11 PM

Interesting. thanks for responding

B668f9e9a60a54c01a275a14b68a843e

(145)

on June 20, 2013
at 03:21 PM

Thanks daz, I'm in the UK so yours and James reply were useful! (Thanks to everyone who replied though, much appreciated)

D396b126240f584bc358e6e4fd84e9e3

(455)

on June 20, 2013
at 03:38 AM

No, not 1,25. The test procedure consists of isolating lymphocytes and measuring growth response in the absence of a particular vitamin or mineral. A slower growth rate (vs the control) indicates a functional deficiency of that nutrient. The test is mentioned in "The 4 Hour Body" and was supposedly used by Lance Armstrong. I've done it several times myself and have found the results very consistent & repeatable over a span of 8 months. Think of it as the HA1c for micronutrient status.

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 01:38 AM

And intracellular D? Is that your 1,25(OH)2D3 level? The active form changes all the time, so it is not a great measure/test.

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 01:34 AM

*plenty*........

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 01:34 AM

Links? I have heard of these alternative theories, but nothing in them matches my personal experience. I still make sure to get linty of sun exposure, even while supplementing D because there are plenty of other known & unknown benefits.

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6 Answers

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2
5e36f73c3f95eb4ea13a009f4936449f

(8280)

on June 19, 2013
at 11:25 PM

Vitamin D's fat soluble, so as long as you have bodyfat, it'll be stored indefinitely. In terms of levels, I've not seen any studies on it, too many individual variables (starting point, inputs of sun/food, ending point), etc. However, in England, they saw population problems at 5 months with a long winter.

best answer

3
543a65b3004bf5a51974fbdd60d666bb

(4493)

on June 20, 2013
at 03:15 AM

There have been a couple on studies done on submariners that i know of,
on a UK crew (dated 1975) & on a US crew (dated 1995).

Both studies are referenced in this study; Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety

here's some text from that study,

Effect of acute onset of ultraviolet light deprivation:
Most of what is known about ultraviolet light deprivation is summarized in Table 3. The most recent data are for an American submarine crew (46), which show a percentage decline in 25(OH)D concentration comparable with that of a British crew reported 20 y earlier (45). The 30-nmol/L decline over 2 months was despite ???a standard US Navy diet which included milk and breakfast cereals fortified with vitamin D??? (46). The initial mean 25(OH)D concentration was higher in the Americans than in the British, consistent with higher vitamin D supplies from diet and sun exposure in Americans.

&

The half-life of 25(OH)D in the circulation is reported as ~1 month in humans (68), the results for the submariners suggest a 2 month half-life (Table 3).

B668f9e9a60a54c01a275a14b68a843e

(145)

on June 20, 2013
at 03:21 PM

Thanks daz, I'm in the UK so yours and James reply were useful! (Thanks to everyone who replied though, much appreciated)

3
Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 19, 2013
at 10:23 PM

Not sure of any studies. I believe that our levels start dropping after a couple of weeks, but it depends how high they were to begin with, as to whether you would end up deficient.

My n=1 experiment: Last Spring, I had a blood level of 91 and decided to stop taking supplements for 3 months & just sun (April- Jun) in Santa Fe, NM. I was out for an hour in a bikini every day around noon. I tested again at the end of Jun and my level had dropped to 57 ng/ml.

57 is great, but my asthma symptoms only go away when I keep my blood level around 80. Needless to say, I restarted supplementation and 3 weeks of 12,000 IUs and I could breath freely again.

Medium avatar

(78)

on July 17, 2014
at 04:07 PM

oh my gosh, so your levels dropped that much even though you were getting a lot of sun exposure? That scares me! An hour is a long time and I thought very suitable for Vitamin D production!

Medium avatar

(78)

on July 17, 2014
at 04:08 PM

Have you ever considered that maybe you were lacking something that helps with D absorption, like magnesium or Vit A? It's just so hard to figure out the right balance!

2
D396b126240f584bc358e6e4fd84e9e3

on June 19, 2013
at 11:24 PM

There are some alternative theories about vitamin D deficiency that are pretty interesting. One of the theories is that supplemental vitamin D may be doing more harm than good in some individuals. Vitamin D supplementation is believed to desensitize the VDR receptors and it's the VDR receptors that are mainly responsible for gene activation. Obtaining vitamin D from sunlight does not appear to desensitize VDR receptors or reduce their numbers. Vitamin D via supplementation can also be immunosuppresive, which may not be optimal for people battling chronic infections.

Here's a strange thing I'm dealing with now:

I began supplementing 6,000 IU a day to increase my 25-hydroxy vitamin D from 35 to 50 ng/ml. However, as I increased my vitamin D via supplementation, my intra-cellular levels of vitamin D (as determined by the Spectracell micronutrient test), dropped like a rock. Despite achieving 57 ng/ml 25-hydroxy, I'm now borderline deficient at a cellular level. When I was at 35 ng/ml, my intra-cellular vitamin D levels were at their highest and at the upper end of normal range.

I'm going to try going down to 2,000 IU a day and getting 30 min of sunlight to make up for the rest. I'll watch the 25-hydroxy levels regularly but I won't know if this approach is effective until I redo the micronutrient test in 4-6 months.

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 01:38 AM

And intracellular D? Is that your 1,25(OH)2D3 level? The active form changes all the time, so it is not a great measure/test.

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 01:34 AM

*plenty*........

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 06:11 PM

Interesting. thanks for responding

D396b126240f584bc358e6e4fd84e9e3

(455)

on June 20, 2013
at 03:38 AM

No, not 1,25. The test procedure consists of isolating lymphocytes and measuring growth response in the absence of a particular vitamin or mineral. A slower growth rate (vs the control) indicates a functional deficiency of that nutrient. The test is mentioned in "The 4 Hour Body" and was supposedly used by Lance Armstrong. I've done it several times myself and have found the results very consistent & repeatable over a span of 8 months. Think of it as the HA1c for micronutrient status.

Ce41c230e8c2a4295db31aec3ef4b2ab

(32556)

on June 20, 2013
at 01:34 AM

Links? I have heard of these alternative theories, but nothing in them matches my personal experience. I still make sure to get linty of sun exposure, even while supplementing D because there are plenty of other known & unknown benefits.

1
5661757f5a7ad1d09c44d7b3ce9b533f

on June 20, 2013
at 05:54 PM

I believe that the half-life of Vit D is usually one to two months. I presume it can vary based upon your own body's particular needs during a period of time, but a half-life of 1-2 months is prob a good starting point for an estimate.

0
6fece842bd1bcf5724f458a302a2156e

on June 20, 2013
at 07:37 PM

I've always thought we could store enough in summer in climates like mine to last us reasonably well over winter even if our stocks get depleted in winter. When the sun is out I lie out in it most days for 20 minutes with very little on.

There are certainly problems in the UK with women who are covered for religious purposes and not in the sun enough. Vit D deficiency on the rise for them here.

(Moral message - Nudity is good for your health)

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