Vitamin D helps your body absorb calcium, and levels often drop in winter due to less sun exposure. When vitamin D is low, your body may start to pull calcium from bones to keep blood levels normal.

Most adults need at least 600 IU of vitamin D every day to maintain healthy levels. Blood levels of vitamin D below 12 ng/mL are considered deficient and can be harmful to health. Vitamin D helps the ...

Hyperthyroidism causes high levels of thyroid hormones in the body. In some cases, people with high thyroid hormone levels may also have higher calcium levels. Thyroid hormones can affect many ...