Research published in the journal Endocrine Connections suggests that vitamin D supplementation in the condition primary hyperparathyroidism might not be such a bad thing.
Primary hyperparathyroidism is a condition where your parathyroid glands have gone “haywire.” An adenoma – a word to describe a non-cancerous tumor – begins growing on your parathyroid, causing your glands to produce too much parathyroid hormone.
Parathyroid hormone (PTH) allows your body to pull calcium from your bones and tells your body to start making more activated vitamin D to absorb more calcium in the gut. This helps your body keep a narrow and healthy range of calcium in the blood. When calcium is just right in your blood, your PTH will lower and stop pulling calcium from your bones.
However, in primary hyperparathyroidism, no matter how much calcium you have in your blood, the parathyroid keeps producing and producing PTH, leading to chronically high PTH levels, high blood calcium (hypercalcemia), and if not treated, bone diseases like osteoporosis and osteomalacia.
Doctors who treat patients with primary hyperparathyroidism are sometimes reluctant to give these patients vitamin D. They worry that vitamin D might further cause blood calcium to rise and put the patient at even higher risk of hypercalcemia. Currently, due to a lack of research, there are no guidelines for how much vitamin D to administer or if to avoid completely for patients with primary hyperparathyroidism.
In this present study, Dr Ranganathan Rao of the University Hospitals Coventry and colleagues observed patients with primary hyperparathyroidism, if they were administered vitamin D and if that led to any adverse outcomes.
The researchers looked at records of patients who attended their clinic between 2003 and 2011. They found 40 patients had vitamin D levels below 20 ng/ml and elected not to have the adenoma removed (a common treatment for primary hyperparathyroidism).
Twenty-eight of the patients were put on vitamin D as part of the treatment plan, 12 were not. While the 28 patients were placed on a variety of vitamin D regimens, a common treatment out of these clinics is to take 40,000-50,000 IU of vitamin D3 once per month.
The researchers observed the patients’ records for a mean 17-18 months. Did they find any adverse outcomes in those who took vitamin D? Here’s what they found:
- Mean baseline 25(OH)D levels were 12.8 ng/ml in the vitamin D group (13.2 ng/ml in the no-vitamin D group).
- Over the varying observation periods of each patient, in the vitamin D group, the mean 25(OH)D level rose to 54.4 ng/ml.
- In the vitamin D group, calcium did not rise, staying the same at a mean of 2.60 nmol/l over the course of the observation periods.
- In the vitamin D group, PTH lowered in 89% of the patients, with a mean decrease of 21% (13.3 to 10.5 pmol/l).
- In the vitamin D group, there were no adverse effects reported.
- In the no-vitamin D group, PTH levels remained the same (15.8±2.7 vs 16.3 pmol/l).
The researchers concluded,
“In conclusion, long-term replacement of vitamin D deficiency with vitamin D in various commonly prescribed preparations effectively reduced circulating PTH levels. This approach may be helpful in patients with mild primary hyperparathyroidism and in patients who are not willing to undergo surgery or have medical contraindications.”
Are we ready to set new guidelines declaring that vitamin D supplementation is okay in patients with primary hyperparathyroidism? Not yet probably. The researchers call for a long-term randomized controlled trial to monitor the effects of vitamin D supplementation in patients with this condition. Also, one limitation of this study is that the researchers excluded patients that elected to have surgery for their condition. Thus, the patients studied likely had a more “mild” primary hyperparathyroidism compared to those excluded.
In the meantime, it looks like vitamin D supplementation shouldn’t necessarily be avoided in primary hyperparathyroidism, as long as the condition and supplementation regimen is closely monitored by a qualified health professional. The researchers close with the advice, “regular monitoring of calcium and 25(OH)D levels is advised” in patients with primary hyperparathyroidism.