Vitamin D doses and testing, help please

[Agapanthus1]

I have some questions about vit D and would be very grateful for your knowledgeable replies.

1. On the vit D council website there is a table that tells you how much vit D to take daily to increase your level to a certain amount. However, it doesn't say anywhere (that I can find) how long you take it for to achieve this level or before testing. Does anyone know?

2. Also, does vit D have a half life? I am sure one of the endos I saw said there was no point in re-testing my vitamin d level after the loading doses at that time due to the half life of the vitamin being either 3 weeks or 3 months (I can't recall)? I am asking because despite taking the recommended dose, my level has dropped rather than increased.

3. Does it matter if you take your vitamin d daily or weekly? I find I tolerate it better weekly.

Look forward to hearing from you 😊

[SeasideSusie Remembering]

Agapanthus1

1) Retest 3 months after starting to supplement. Once the recommended level is reached (Vit D Council recommends 125nmol/L [50ng/ml], Vit D Society recommends 100-150nmol/L [40-60ng/nl]) then you'll need a maintenance dose to keep it there, which may be 2000iu daily, maybe more or less, maybe less in summer than winter, it's trial and error so it's recommended to retest once or twice a year to keep within the recommended range. You can do this with a private fingerprick blood spot test with an NHS lab which offers this test to the general public:

vitamindtest.org.uk/

2) Having a quick look on Google, it seems that Calcitriol - the active form of Vit D has a half life of 15 hours and Calcidiol - the precursor/semi-activated - is said to have a half life of 15 days.

There is a graphic here showing Vit D synthesis:

uspharmacist.com/article/vi...

The Vit D Council says that bodies can produce 10,000 to 25,000 IU of vitamin D in just a little under the time it takes for our skin to begin to burn. Vit D is stored, so if you make enough natural Vit D from the sun during the summer, this gets stored in the body's fat cells and stays inactive until it is needed and then the liver and kidneys turn the Vit D into the active form. If you need to supplement you just find the dose you need to maintain your level.

If your level has dropped despite taking the recommended dose, what form of D3 are you taking? You have Hashi's so are you taking an oral spray or sublingual drops for best absorption? And are you taking magnesium - we need Magnesium so that the body utilises D3, it's required to convert Vit D into it's active form. So it's important we ensure we take magnesium when supplementing with D3.

3). Daily or weekly dosing seems to achieve very similar benefits so choose which you prefer

vitamindwiki.com/Take+vitam...

[Agapanthus1 in reply to SeasideSusie]

Thanks so much for your detailed reply.

Yes I am taking magnesium (my levels are good) and Mk 7.

I am taking a tablet form of D3 as I could not find a spray with a high enough dose to take weekly.

My level went up really nicely at first but has slowly dropped so perhaps not absorbing as well now (strange)! I am aiming for 50-60 ng, at about 36 ng now. I will persist though!

Thanks so much x

[Hidden]

It has taken me two years to reach 100 level up from 25. I take soft gels 5000 mcg every day and then retest after 3 months, this way I keep at around 100 level. If it reaches 100, I just take 1000 mcg every day for a few months. Take with K2 these two work together to direct your calcium into your bones and teeth and not into your soft tissues. Take both with the fattest meal of the day. Everyone is different it depends on you.

[Agapanthus1]

Thank you for your reply. Hope you are feeling well 😊