VDC test kit slider
VDC test kit slider
sperti logo 1
Text size A A A
High contrast on off

Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Study: New insight into vitamin D, calcium relationship

Research presented last week at the 94th Annual Endocrine Society meeting shows that vitamin D supplementation therapy is safe for patients with high serum calcium levels.

Lead author Dima Abdelmannan, MD, an endocrinologist at Cleveland Veterans Affairs (VA) Medical Center, and colleagues conducted a 1 year study in which 10 women and 22 men were supplemented with vitamin D.

All participants in the study started with vitamin D levels below 30 ng/mL and had hyperparathyroidism, a condition which affects how much parathyroid hormone the body produces, which controls serum calcium production.

All patients also had hypercalcemia, characterized by calcium levels above 10.1 mg/dL. Doctors are often cautious about suggesting vitamin D for patients with hyperparathyroidism because of a perceived increased serum calcium risk.

Abdelmannan and colleagues measured vitamin D, calcium serum levels, and parathyroid hormone throughout the study. Patients received 3,630 IU of vitamin D2 or D3 daily.

Vitamin D levels returned to normal during the course of the study. Calcium levels reportedly remained practically unchanged. Average serum calcium was 10.7 ng/dL before treatment, at 6 months it was 10.6, and 12 months average was 10.7.

Parathyroid hormone decreased from an average 124 pg/dL to 103 pg/dL at 12 months. Unfortunately, the researchers did not report whether vitamin D2 or D3 raised blood levels most effectively.

Hyperparathyroidism affects 1 out of every 1,000 people, while it is 3 times as likely in women as men. Hyperparathyroidism can lead to decreased bone density, increased serum calcium, kidney stones, mood changes, and gastrointestinal problems. Depending on the type of hyperparathyroidism, treatments vary from surgery to supplementing with high dose vitamin D2 or D3.

The authors suggest patients with primary hyperparathyroidism treat with vitamin D while monitoring vitamin D, calcium, and parathyroid hormone levels.


Abdelmannan D, Leciejewski K, Ajlouni H, Pascuzzi K, Arafah BM. Vitamin D supplementation in vitamin D deficient patients with primary hyperparathyroidism: Impact on calcium and parathyroid hormone levels. Reviews. June 2012.