Iron deficiency: the most common cause of unexplained fatigue

Two different things

You can be short of iron without being anaemic. Iron stores, measured by ferritin, fall first; only later does haemoglobin drop and true anaemia appear. Low stores alone can already cause fatigue, hair shedding and restless legs.

Symptoms

• Fatigue out of proportion to activity
• Breathlessness climbing stairs
• Pale skin, brittle nails, hair loss
• Headaches, poor concentration
• Craving ice or unusual non-food items

Finding the cause matters more than the tablet

In menstruating women, heavy periods are the usual explanation. In men and in women after menopause, iron loss from the digestive tract must be investigated, since it can reveal an ulcer, coeliac disease or a bowel tumour. This is why doctors ask about stools and often recommend an endoscopy.

Taking iron properly

Take it with vitamin C, away from tea, coffee, calcium and dairy. Every other day dosing is absorbed better than daily dosing and causes less constipation. Stores take three to six months to refill, so continue after the blood count normalises.