Hi MIO ,
Yes , guidelines within the NHS are a bit confusing , your doctor has looked at 50 and decided that you didn't need any supplementation , because guidelines say that 50 to 200 is the acceptable level. You were at the very lowest acceptable level , after a 2 week sunny holiday .... that should have told him that your normal level, i.e. without plenty of sunshine was likely to be a lot lower.
IF spending a few pounds on your future health is possible. In your situation , I would get a vitamin D test , and measure your blood level, and that of your child. The doctor may do it , but it does not sound too hopeful, from what you have said.
You can get a blood test, a blood spot on blotting paper , sent to this NHS lab. www.vitamindtest.org.uk/. They do charge £29 IF not doctor ordered. They reply by email within a week.
From those results, you can calculate what dose you, and your child need. AS FOLLOWS .
For a 75 KG adult , if you supplement , daily , long term , i.e. every day - continuously . You can expect , on AVERAGE , that your blood level will rise by 25 ( nmol/L in UK units ) per 1000 IU. . So lets say your measured level came back as 40 , then by supplementing with 3000 IU ( 75 micrograms ) per day , you would expect your level to rise to just above 100. i.e by 75 nmol/L , up to around 115.
Children need less Vitamin D , the requirement is by weight , in total from sun, foods and supplement , we need about 70 IU of Vitamin D3 per kilo of our weight. Lets say your child is 25 kg , and she will get some from food , ( not much ) and some from sunlight , but none between mid -Oct and mid-April, from sunlight ( see my explanation below ) then by giving her 1000 IU ie. 25 micrograms per day , you will be raising her blood level , on AVERAGE , by about 75 nmol/l.
After a period of about 3 months , you both will have come to an equilibrium level, where your Vit D blood level will stabilize on that particular dose that you are taking. THEN , I would recommend that you again test your blood levels , with the same organisation , this will mean you will know for certain that the supplements have worked as required. Many of us do have responses different from the average.
NHS guidelines for blood levels are 50 -200 , mostly , so you will be in just about the sweet spot. There are many health benefits , to being replete in Vitamin D , as you no doubt have seen in your research.
I wonder if you are vegetarian , veggie foods contain practically no Vit D , that may be a reason that you tend to have low levels. There are other reasons , High BMI , genetic factors , etc etc. .
One other reason, could be hyperparathyroidism , IF you find that your level of Vit D , is very low , when you initially test , ie. below 30 , then I would say you should , at some point get a blood serum calcium test , after you have been supplementing for several months, Maybe your doctor has already done this ? he would have been looking for hypercalcaemia,, It is very unlikely , but could possibly mean problems with the parathyroid glands. I stress very unlikely , especially pre-menopause. IF your calcium blood level is higher than normal , above 2.5 mmol/l , then , your doctor should do something about it, and you should not take vitamin D , except under medical supervision. I must stress , that this is very very unlikely , but has to be mentioned. Hyperparathroidism can suppress vitaminD blood levels.
You could take the supplement as a capsule , i.e. gelatin with vitD3 in olive oil, or possibly an oral spray . The sprays generally come in 1000 IU and 3000 IU sizes . They are easy for children, because they taste nice . perhaps you could have one each , of 3000 IU and 1000 IU. ..!
* The reason sunlight does not have VitaminD , during winter, mid -Oct to mid-April, is that the UVB is absorbed by the atmosphere whenever the suns' elevation is below 45 degrees. Which in the UK , means all winter , AND also early morning and early evening. So there is no UVB present outside the hours of 11am to 3 pm ... even in summer. Because of our high latitude of over 50 degrees North. This is all basic physics !
Also , remember , sunscreens absorb UVB light , that is their very purpose, and so prevent your skin making vitamin D . So leave off sunscreen for 20 mins , in the sun, during those hours mentioned above. However , as you know , it is not a good idea to burn , your skin can only make vit D for 20 mins , in strong sunlight , it then becomes saturated , until the following day. So there is no point in baking for hours in strong sun.
Whew
I hope some of that was useful, !
I do post quite a bit here on Mumsnet , about Vitamin D , search my nick, or get back to me if you have any questions.
Here is a thread , with lots of useful information. I posted there quite a bit . www.mumsnet.com/Talk/general_health/2841497-If-you-are-vitamin-D-deficient-what-have-you-been-prescribed
best of luck
BTBH
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