Calcium isn't usually tested to determine hyperthyroidism. You need to have thyroid hormones tested to determine thyroid status. That would be TSH, Free T4 and Free T3. Have you had those tested? If so, please post the results with corresponding reference ranges. Also, please post any antibody tests or ultrasound results you might have.
Vitamin D is necessary for the proper absorption of calcium, which could explain your osteoporosis diagnosis. Magnesium and vitamin K are also necessary for proper absorption of calcium, so those may be factors, as well, as well as adequate exercise and diet.
If it's parathyroid; you're in the right forum.
Just to be clear... Free T4, Free T3 and TSH are related to thyroid function. Calcium and PTH are related to parathyroid function.
The thyroid and parathyroids have nothing in common except their location in the body. Their functions are totally different.
The thyroid controls metabolism, heart rate, body temperature and other functions, while the parathyroids control the electrical impulses in the body, in which calcium plays a part.
What are your blood calcium and PTH levels? High urine calcium can indicate hyperparathyroidism, which may be what you meant in your original post? However, according to NIH, urine calcium may not correlate with blood calcium and PTH.
Vitamin D supplementation is, typically, contra-indicated if you have hyperparathyroidism, so that should be ruled out prior to taking vitamin D supplements.
It should be noted that osteoporosis is, typically, caused by lack of calcium and other bone boosting nutrients. Lack of estrogen can also cause osteoporosis. Teen girls/young women who restrict eating and lack menstrual cycles are at risk of osteoporosis.
Have you had estrogen levels tested?
Optimal calcium absorption occurs with a vitamin D level greater than 32 ng/mL (79.8 nmol/L).That you have high levels of urine calcium with vitamin D deficiency...something isn't right there.
Excerpt from Medline Plus - Calcium - urine...
"High levels of urine calcium (above 300 mg/day) may be due to:
Chronic kidney disease
High vitamin D levels
Leaking of calcium from the kidneys into the urine, which causes calcium kidney stones
Taking too much calcium
Too much production of parathyroid hormone (PTH) by the parathyroid glands in the neck (hyperparathyroidism)
Use of loop diuretics"
Excerpt from Better Bones...What’s the cause of your osteoporosis? Diagnostic tests and what they mean...
"24-hour urine calcium excretion test
This test looks at how much calcium is being excreted in the urine. For this test, you collect all your urine over 24 hours in a large container for laboratory analysis to measure the amount of calcium in the total volume of urine. Excessive urinary calcium excretion is a common cause of bone loss and osteoporosis.
What your results tell you: The normal laboratory range for a person eating an average diet is around 100 to 250 mg of calcium lost in the urine each day. I consider a calcium loss of more than 250 mg to be a concern. In such cases, the first step is to stop all calcium supplements for 4 to 5 days and then retest the 24-hour urine calcium. If the urine calcium loss is still high, then steps should be taken to reduce this loss of calcium in the urine, as it can cause bone loss. Nutritional, lifestyle, and medical approaches can help."
CALCIUM- URINE 24h 322 mg/24h (upper limit 250)
PHOSPHORUS- U 24h 1038 mg/24h (upper limit 1300)
CREATININE- U 24h 1750 mg/24h (upper limit 2000)
CORTISOL-U FREE 24h 283.9 nmol/24hr (upper limit 208)
Last cortisol value was normal 206.1 nmol/24hr, under 208.
CELIAC SCREEN 1.7 U/ml (upper limit 40 U/ml)
Finally - did an ultrasound of the thyroid gland and no abnormalities.
I'm buffled ....
Well that that is a much better result with your urine calcium although still a bit high. Cortisol is the stress hormone so can rise due to stress. I found this article which is very interesting.
Are you losing too much calcium in your urine? by Dr. Susan E. Brown...
"Do you have hypercalciuria?
Luckily, there’s a fairly simple laboratory test to determine if you’re losing calcium. You’re asked to collect your urine over 24 hours and submit it for chemical analysis to determine how much calcium it contains. Most labs consider any 24-hour calcium loss over 250–300 mg of calcium to be excessive.
If your 24-hour urine calcium comes back high, don’t panic: You may have gotten that result simply because you are taking too much calcium. When there’s an unusually high consumption of calcium from diet and supplements, the body simply moves unneeded calcium from the body into urine to get rid of it. Your doctor will likely recommend you retake the test, but this time avoiding all calcium supplements (and probably also dairy foods) for a week before again collecting your 24-hour urine sample.
If your re-test shows you’re genuinely losing calcium, again: don’t panic. Excessive calcium loss in the urine can be due to factors like high intake of salt, caffeine, soda, or sugar, low levels of nutrients like magnesium, vitamin D, and vitamin K, and even prolonged stress. These factors all promote an acidic pH (which promotes calcium loss), and they’re all things you can begin correcting on your own."