Calcium is important for many functions in the body, including keeping your bones healthy and strong. More than 99 percent of the body's calcium is stored in the bones and teeth, while the remaining one percent is found in the blood.

Alcohol disrupts calcium balance in many ways. For example, alcohol exposure increases parathyroid hormone (PTH) levels. PTH is a hormone that regulates the metabolism of calcium in the body. In cases of chronic alcohol abuse, blood levels of parathyroid hormone can remain very high which strains the body's calcium reserves. Continuously high PTH levels can lead to a condition called secondary hyperparathyroidism, which depletes calcium stores even further.

Alcohol can also stop vitamin D converting to its active form. Vitamin D helps regulate calcium balance in the body, so this interference in vitamin D metabolism results in decreased calcium absorption. Vitamin D deficiency can lead to osteomalacia, a bone condition associated with pain, fractures and deformity.

Chronic heavy drinking can result in hormonal deficiencies in both men and women. Men who drink too much alcohol tend to produce less testosterone, a hormone known for its positive effect on bone density. Low testosterone levels have also been linked to decreased activity of osteoblasts, which are cells that help bone growth.

In pre-menopausal women, heavy drinking can result in irregular menstrual cycles, which increases the risk of osteoporosis. However, post-menopausal women may be an exception to the rule. Alcohol increases the conversion of testosterone into estradiol, a hormone commonly used to prevent bone loss after menopause. For this reason, alcohol consumption may actually have a positive effect on bone density in women after menopause.

High levels of cortisol are also common in people who drink too much. Cortisol is a hormone which gets released when people are under too much stress. High levels of cortisol lead to inflammation and premature aging of the body. Excessive levels of cortisol have also been linked to decreased bone formation and increased bone resorption – the breakdown of bones. Cortisol can also impair calcium absorption which leads to an increase in PTH secretion, resulting in further bone loss.

Due to the effects of alcohol on balance, alcoholics tend to suffer from falls more frequently than other people. Heavy alcohol consumption has been associated with an increased risk of fracture, including hip fracture, in both men and women.

Spinal fractures, which tend to be uncommon in individuals under fifty years of age, are more prevalent in those younger than fifty who abuse alcohol. Alcohol consumption has also been linked to other types of fracture, including those of the wrist and ribs.

The most effective treatment for alcohol-induced bone change is abstinence. Abstinence has been shown to mostly result in a rapid recovery of the function of bone-forming cells. Studies have also demonstrated that the actual loss of bone may be partially restored when alcohol abuse is discontinued.