Hi OP ,
It is most likely that your hyperparathyroidism is secondary. Which can be caused by renal problems, long term lithium treatment , mal-absorption of vitamins and minerals, low vitamin D etc etc. There is a 2% chance that you have normocalcaemic primary hyperparathyroidism.Which is sometimes considered to be an early stage of full blown primary hyperparathyroidism.
IF you were to be measured with high blood calcium , then statistically there is a 99% chance that you have primary hyperthyroidism , caused by overactive parathyroid gland or glands (of which you have 4 ) . BUT you didn't have high calcium, so that does NOT apply, unless you subsequently get high calcium levels. Above 2.5 mmol/L, ( at your age.)
Obviously your doctor has the full facts , regarding blood tests, your medical history and it appears from that, he has concluded that you have secondary hyperparathyroidism due to reduced vitamin D
ASSUMING that is the case , and it does seem overwhelmingly likely, then to counteract that cause, you should try to ensure you have sufficient VitaminD3 , in your system, and that you have enough calcium in your diet/supplementation. When this is the case , then your parathyroid hormone PTH , should drop to mid range or even below. OFTEN , in this country , because of the prevalence of low vitD , PTH is higher than that , which can, in some circumstances, lead to osteopenia, osteoporosis and osteomalacia.
You probably know that there is some controversy about how much vitaminD we require to become replete. Many vitaminD researchers say a blood level 100 -150 is optimal. Sometimes you might be told that 50 is ok, more recently 75 has been adopted by some parts of the health service. It is slowly changing , and going up. Which is good. The human natural level is about 120-140 , that's what we achieve when we live in sunshine , as we did for millions of years , in sunny Africa. We evolved to have those kind of levels , we get them now , when we are in that sort of environment. Every cell in your body has a receptor for vit D , 2000 of your genes have vitamin D response elements , you need the right amount , to remain healthy.
FOR yourself ... bearing in mind that you do have absorption problems , then I might suggest you use an oral spray ...this is absorbed direct into the blood stream. It does not go through your digestive system. 4000 IU per day , long term would seem just fine . After about 60 - 90 days , your blood level should settle at it's equilibrium , for that daily supplementation dose . It would then be a good idea to measure, Vit D and PTH , and calcium. This will tell you if you have responded. DO NOT just suddenly stop VitD supplementation , maybe your blood level will come back as 170 , which is not harmful at all, many people reach that in just sunshine. You might like to reduce your daily dose by 500 or 1000 IU , if you are responding so well. You may be a weak responder , some people are. You may need more , say an extra 1000 IU. By taking a measurement you can decide the best course of action . We have a 6:1 variability in our response to supplementation.
When your blood level of vitaminD ( calcidiol) reaches 80 or above , then your gut cells become maximally efficient at enabling the regulation of calcium extraction from your food. Daily you require about 200 mg of calcium , to replace that lost by excretion etc. The efficiency with which you extract calcium from a diet containing say 1000 mg of calcium would then be 20%. IF you are low in Vitamin D , you may not be able to turn up your rate of extraction , it may peak at only 15% , say , THEN , you can only receive 150 mg from your diet , then your bones weaken and donate the rest ( 50mg) , under the direction of a raised PTH level, in order that your calcium blood level continues to remain 'normal'. That is the process that may go on with low vitamin D . You can now avoid it .
IF your diet is low calcium , then it might be useful to increase it.
I have posted quite a bit here on Mumsnet about Vitamin D , have a look at some of my old posts for lots more information . Or get back to me for more info.
Here is one where I explained in more depth about this very important subject. www.mumsnet.com/Talk/general_health/2841497-If-you-are-vitamin-D-deficient-what-have-you-been-prescribed
A long read , but very informative.
Best of luck , hope that was useful. PHEW.
BTBH
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