Bone Health and Osteoporosis: Why Calcium Alone Is Not Enough

 

Osteoporosis — the progressive loss of bone density and strength leading to fragile bones that fracture with minimal trauma — is typically thought of as a disease of elderly Caucasian women. This perception has led to significant underdiagnosis of osteoporosis in Black African populations, including Ghanaians. While it is true that people of African descent generally have higher peak bone density than Caucasians, osteoporosis does occur in Ghanaians and is significantly underdiagnosed and undertreated. As Ghana's population ages, fracture-related morbidity and mortality from osteoporosis will grow.

The Biology of Bone

Bone is not an inert structure — it is dynamic, living tissue in a state of constant remodelling. Specialised cells called osteoclasts break down old bone (resorption) while osteoblasts build new bone (formation). This remodelling cycle renews the entire skeleton approximately every 10 years. Peak bone mass is achieved by the late 20s to early 30s — making the first three decades of life the critical investment period for skeletal health. After approximately age 35, bone resorption gradually exceeds formation, and bone density slowly declines. At menopause, the accelerated withdrawal of oestrogen triggers a period of rapid bone loss that can last 5–10 years.

Risk Factors for Osteoporosis

Non-Modifiable

• Increasing age

• Female sex (women have lower peak bone mass and experience menopausal bone loss)

• Family history of osteoporosis or hip fracture

• Previous fragility fracture (a fracture occurring from a fall from standing height or less, which in a healthy young person would not cause a fracture)

• Early menopause (before age 45), whether natural or surgical

Modifiable

• Inadequate calcium intake throughout life

• Vitamin D deficiency (as discussed — endemic in Ghana despite sun exposure)

• Physical inactivity: Weight-bearing exercise (walking, running, dancing) is the most powerful stimulus for bone formation

• Smoking: Directly toxic to osteoblasts

• Excessive alcohol consumption

• Low body weight: Thin individuals have less mechanical loading on bones and lower oestrogen levels from adipose tissue

• Long-term corticosteroid use: Prednisolone and other steroids are among the most powerful drivers of secondary osteoporosis — every patient on long-term steroids should have bone protection

Secondary Causes

Many medical conditions and medications cause bone loss and should be investigated in any patient with unexpectedly low bone density:

• Hyperthyroidism and over-treated hypothyroidism (excessive thyroxine)

• Hyperparathyroidism — elevated PTH causes osteoclast activation and bone resorption

• Malabsorption conditions (coeliac disease, chronic pancreatitis) preventing calcium and vitamin D absorption

• Chronic kidney disease — impairs vitamin D activation

• Long-term anticonvulsant therapy, proton pump inhibitors, and heparin

Blood Tests for Bone Health Evaluation

• Serum calcium and phosphate — screen for hyperparathyroidism and metabolic bone disease

• Parathyroid hormone (PTH) — elevated in primary hyperparathyroidism and vitamin D deficiency; suppressed in hypercalcaemia of malignancy

• 25-hydroxyvitamin D — as discussed; deficiency is the most common modifiable cause of bone loss globally

• Alkaline phosphatase (ALP) — elevated in active bone turnover (Paget's disease, healing fractures, osteomalacia)

• Thyroid function (TSH, free T4) — hyperthyroidism and over-treated hypothyroidism both cause bone loss

• Testosterone in men — hypogonadism is a common cause of osteoporosis in men

• Urine markers of bone resorption (CTX, NTX) — used to monitor treatment response in established osteoporosis

DEXA Scan: Measuring Bone Density

Dual-energy X-ray absorptiometry (DEXA) is the gold standard for measuring bone mineral density. It is a low-radiation X-ray scan of the hip and lumbar spine that takes approximately 15 minutes. The result is expressed as a T-score: the number of standard deviations above or below the mean peak bone density of a healthy young adult. A T-score above -1.0 is normal. Between -1.0 and -2.5 is osteopaenia (low bone density). Below -2.5 is osteoporosis. DEXA scanning services are available at major hospitals in Accra and Kumasi.

Building and Protecting Bone

• Calcium-rich diet: Dairy products, small dried fish (eaten with bones), dark green leafy vegetables (kontomire, ayoyo), fortified foods

• Adequate vitamin D: As discussed — supplementation is often necessary

• Regular weight-bearing exercise throughout life — not just for the elderly

• Avoid smoking and excessive alcohol

• Medications: In established osteoporosis, bisphosphonates (alendronate, risedronate) are highly effective at reducing fracture risk and are increasingly available in Ghana

�� Bone loss is silent until a fracture happens. If you are post-menopausal, on long-term steroids, or have other risk factors, ask for bone health blood tests and discuss DEXA scanning with your doctor.

�� Get instant interpretation of your lab results — visit https://VincentAkwas.github.io/lablens — free, detailed clinical commentary for every value.