hi again Gower,
Yes , 29 nmol/L is low enough to cause aches pains, joint problems etc in some people.
Vit D is transformed in the body to Vit d hormone, which your body uses to read genes in almost every cell in your body. Over 2000 of your 23000 genes have vitd response elements. IF for any reason your cells cannot uptake enough of that hormone or its precursor from the blood , the cells will not operate as they should , and some kind of malfunction will occur. It may well be that your low level has hindered some process or other. We know that bone metabolism, and muscle metabolism is associated with some of these vit d processes.
Amongst hundreds of different functions , Vit D enables your gut to regulate the uptake of calcium. IF you are low, you may not be able to absorb enough calcium from your food , especially if you eat a low calcium diet ( i.e. dairy free ). Green veg etc contains calcium , you should ensure that you get sufficient calcium , and magnesium from your diet. IF , this is your situation , then you may find that your calcium reservoir in the body i.e. your bones , donates calcium to your blood , to keep the blood level exactly where it needs to be. This may cause aches and pains in the bones, it is a condition called osteomalacia. Pressing on the sternum, or a few inches below the knee , on the front of shin might show this up as pain or tenderness.
Over the long term , if the bones continue to donate calcium to the blood , then osteopenia , osteoporosis may develop.
Some recent research , in the U of Nebraska also Harvard , has found that ensuring that the diet contains enough protein will help in rebuilding bones. The current recommendation for 0.8 gram of protein per kilogram of body weight , does not appear to be sufficient to supply enough protein to rebuild the bone matrix. ( collagen ) Their results indicate that you may need 1.2 g of protein per kg.
Although this may or may not be your particular problem , it is worthwhile ensuring you do have a good healthy level of vitamin d . It will protect you from many nasty diseases.
Up above someone mentioned doses.
2.5 ug ( microgram ) of vitamin d is 100 IU
25 ug (microgram ) is 1000 IU
An average responder , will raise their vitamin d levels in the blood by 25 (nmol/l in UK units . ) IF they supplement by 1000 IU per day in the long term , daily , ie. 25 ug.
IF you simply take a large loading dose , for a few weeks, then stop all dosing , your level will spike up , then slowly come back to the original level, depending upon your lifestyle , food etc. That is why many people say that they have recurrent problems with low vitamin D.
Your body requires around 65 - 70 IU of Vit d per kilogram of weight , per day . That is from all sources. Food , sunlight and supplement. You will not get much from food. Vegetarian foods contain none , unless artificially fortified. An egg contains just 40 IU . enough for a chick.
In the UK , food and sunlight does not really give you the chance to get enough. Wild oily fish, has some, but you would need to consume it every day to get enough. Meat has some , but not large amounts. It somewhat depends upon how the animal was kept , and/or supplemented. Sunlight ... at the times shown above is the best way to build vit d reserves. However, you must not burn, that is very detrimental to the skin. In strong sunlight any particular area of skin is saturated with Vit D , in 20 minutes. So there is no point in baking for long periods in strong sunlight. Overall, a healthy human skin can make 10,000 to 20,000 IU in about an hours sunbathing.
However in winter, other methods must be used.
Is that useful. Hope so !
Best of luck
BTBH.
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