The need for calcium and Vitamin D for healthy bones

Osteoporosis is a common bone disorder that causes a progressive loss in bone density and mass. As a result, bones become thin, weakened, and easily fractured.  A large number of osteoporosis - associated (or “osteoporotic”) fractures occur primarily of bone within the spine (the vertebrae), the hip, and the forearm near the wrist.

A number of treatments can help to prevent loss of bone and treat low bone mass. However, the first step in preventing or treating osteoporosis is to consume foods and drinks that provide calcium, a mineral essential for bone strength, and Vitamin D, which aids in calcium breakdown and absorption.

Good nutrition is important at all ages to keep the bones healthy. Taking calcium reduces bone loss and decreases the risk of fracturing the vertebrae (the bones that surround the spinal cord) and consuming calcium during childhood (for example in milk) can lead to higher bone mass in adulthood,  increase in bone density which can reduce the risk of fractures later in life.

Calcium also has benefits in other body systems by reducing blood pressure and cholesterol levels, and when combined with Vitamin D supplements, it has been shown to help prevent tooth loss in older adults.

The primary sources of calcium in the diet include milk and other dairy products, such as hard cheese, cottage cheese, or yoghurt, as well as green vegetables, such as kale and broccoli.

Premenopausal women and men should consume at least 1000 mg while postmenopausal women should consume 1200 mg (total diet plus supplement).  Cottage cheese and ice cream contain approximately 150 mg of calcium per 120 ml. Other foods, such as dark green vegetables, some nuts, breads, and cereals, supply an average of 200 mg of calcium daily. Some cereals, soy products, and fruit juices are fortified with up to 1000 mg of calcium per serving.

Some patients do not adequately absorb nutrients from the gastrointestinal tract (due to a condition called malabsorption) and may require more than 1000 mg of calcium per day. In such cases, a healthcare provider will help to determine the optimal dose of calcium.

In these patients, it is usually easily tolerated when it is taken in divided doses several times per day. Some people experience side effects related to calcium, including constipation and indigestion. Calcium supplements interfere with the absorption of some other medications; therefore, medical advice should be sought if one is taking calcium supplements alongside other medications.

There is evidence that dietary calcium intake is a protective factor against kidney stone formation.  Low dietary calcium intake can increase one’s risk of forming kidney stones 

However, use of calcium supplements may increase the risk of kidney stones in susceptible individuals by raising the level of calcium in the urine. This is particularly true if the supplement is taken between meals or at bedtime. Hence, regular follow up is needed for an individual taking calcium supplements to prevent this.

Vitamin D decreases bone loss and lowers the risk of fracture, especially in older men and women. Along with calcium, Vitamin D also helps to prevent and treat osteoporosis. To absorb calcium efficiently, an adequate amount of Vitamin D must be present.

Vitamin D is normally made in the skin after exposure to sunlight. The current recommendation is that men over 70 years and postmenopausal women consume at least 800 international units of Vitamin D per day. Lower levels of Vitamin D are not as effective while high doses can be toxic, especially if taken for long periods of time.

Vitamin D is available as an individual supplement and is included in most multivitamins and some calcium supplements. Milk is the best dietary source of Vitamin D, with approximately 100 international units per cup.

Some other foods and drinks that have a lot of Vitamin D include; orange juice, yoghurt with Vitamin D added, cooked salmon or mackerel, canned tuna fish, cereals with Vitamin D added and cod liver oil.

Dr Ian Shyaka ,  Resident in Surgery, Rwanda Military Hospital,