Effects of vitamin deficiency

Vitamins support different body processes, so a deficiency can affect blood cells, the nervous system, energy production or tissues. Vitamin B12 deficiency may cause fatigue, generalised weakness, dizziness, memory problems or pins and needles. It can contribute to anaemia and, when prolonged, peripheral neuropathy. Coeliac disease and other absorption problems can make deficiency more likely. These symptoms overlap with many conditions, so a symptom does not identify the missing vitamin by itself.

Book a medical assessment if symptoms persist, recur or interfere with work, walking or concentration. Your clinician may ask about food intake, alcohol, medicines, digestive symptoms, previous surgery and conditions that affect absorption. Blood tests can check for anaemia and particular vitamin levels, with further tests when needed. Do not start several supplements at once before testing unless advised, because treatment can obscure the cause or create harmful excess. Keep a list of medicines and supplements for the appointment.

Seek urgent help for sudden confusion, fainting, new one-sided weakness, severe breathlessness, chest pain or rapidly worsening difficulty walking. Arrange prompt review for progressive numbness, balance problems, persistent vomiting or marked tiredness with pallor. Nerve symptoms deserve attention because some causes can become harder to reverse when treatment is delayed, while sudden neurological symptoms may signal an emergency unrelated to a vitamin deficiency.

Ask which deficiency is suspected, which blood tests will clarify it, whether anaemia or absorption problems such as coeliac disease need checking, and how treatment will be monitored. Ask whether numbness, memory changes or dizziness change the urgency, and when you should return if symptoms do not improve.