hi hatenighttime !
Yes you are right , a blood level of 50 , in UK units of nmol/L is pretty low for this time of year.
Be careful not to confuse units , the info posted up above from the <a class="break-all" href="//www.vitamindcouncil.org/i-tested-my-vitamin-d-level-what-do-my-results-mean/" rel="nofollow" target="_blank">Vitamin D council</a> , (an American website) talk predominantly in American units of ng/ml , i.e nanogram per millilitre. Where they say that 50 is good , they mean 50 ng/ml , which is the same as 125 nmol/L when measured over here in the UK in our different units of nanomol/L. ( nmol/L). So, in UK units, a level 125 nmol/L is good ... a level of 50 nmol/L is pretty low. Unfortunately, it is however quite a common level at this time of year for us in the UK. To convert from American units to UK units just multiply by 2.5.
I'm glad to hear you have read a few of my posts concerning vitamin d , where I point out that our physiology is attuned to higher levels than those that commonly prevail in most Western people. Our indoor lifestyle and our high latitude combined with anti-sunlight attitudes, often combined with suncreams and continuously covering skin by clothing etc inevitably means we don't reach blood levels that prevailed throughout our evolution.
By having evolved white skin , many of do have to be more careful in strong sunlight, burning or overexposure is very detrimental, but conversely avoiding sunlight such that we have low levels of vitamin D is also detrimental to our health. A Swedish study, of 29,000 women , showed that sun avoidance was equivalent to smoking in terms of detrimental health outcomes. <a class="break-all" href="//www.ncbi.nlm.nih.gov/pubmed/24697969/" rel="nofollow" target="_blank">See Here</a> and <a class="break-all" href="//www.ncbi.nlm.nih.gov/pubmed/26992108" rel="nofollow" target="_blank">Here</a>
As I have previously pointed out on Mumsnet , blood levels of about 120 -140 nmol/L are normal for us, a species of Great Ape, that arose in Africa over millions of years . Practically every cell in our body has a receptor for vitamin D , over 2000 of our genes have Vitamin D response elements. Strong daily sunlight at those latitudes below about 33 degrees kept our blood levels around 120 -140 .
Indeed , if we replicate those conditions for a Westerner , then levels rise to those ancient levels even for todays lifeguards , outdoor workers etc etc.
Over that last few years , Vitamin D research has shown that below 100 nmol/L is not a good place to be. It makes a great deal of sense to try and ensure your level is around 120 -140 , and even somewhat higher is still a perfectly normal level found in some outdoor living people.
Supplementation is likely to be the most convenient means of achieving that , here in Northern latitudes. Although we do get some sun , not nearly enough here in the UK, at latitudes above 50 degrees, where UVB is absent from sunlight from mid-Oct to mid-April. Our food , contains very little , it is not big natural source. Wild caught oily fish does have some , some meat product have some , but none in fruit and veg. Eggs have a tiny amount , just 40 IU . Enough for a chick...!
In strong sunlight , our bodies can produce 10,000 to 20,000 IU per day, in just a short period of sun exposure. Any particular area of skin is saturated in about 20 mins. So no need to burn or overexpose.
Those that supplement can expect their blood level to rise from their pre-existing level by 25 nmol/L for every 1000 IU of daily supplementation. It will take roughly 2 to 3 months to stabilise for a continuous daily dose. IF you stop , then your level will likely just drop , to your natural pre existing level , unless you make some lifestyle changes , ie. more sun, lots of oily fish etc.
Many people get a prescription from a doctor , take it for a few months , their aches and pains go , then they stop. That is a big mistake. Continuing with a maintenance dose is preferable.
OP, IF your original level was about 50 , then , in my opinion , you should consider taking at least 3000 IU per day for 3 months , then measure your level. If it is below 120 , then increase your dose by say 1000 IU until you keep above 120. On your new daily dose , check your level after about 3 months.
Response can vary, by as much as 6 to 1 . The figures I have given are an average, for an average responder, you may be different , therefore , I do suggest you check your levels with a vitamin D test. Your doctor may co-operate, he may not ... however you can get private tests . Here is one lab , it is an NHS lab , at Sandwell , a blood spot on blotting paper , sent to them , with results emailed back within a week. <a class="break-all" href="http://www.vitamindtest.org.uk/" rel="nofollow" target="_blank">www.vitamindtest.org.uk/</a> Unfortunately they do charge £29 IF the test is not doctor ordered.
Best of Luck,
hope this proves helpful ,
BTBH
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