Lack of vitamin B1
Significant thiamine deficiency can be detected by signs of fatigue, weight loss, irritability, memory problems, and loss of appetite. A severe thiamine deficiency will affect the nerves, muscles, heart and brain.
The people most prone to serious vitamin B1 deficiency are young adults with severe anorexia, people who consume large quantities of alcohol and people whose diet lacks variety and is essentially made up of highly processed carbohydrates (white rice, white flour, white sugar).
Certain conditions, such as prolonged diarrhoea, can also lead to a vitamin B1 deficiency.
Lack of vitamin B2
The symptoms of a lack of vitamin B2 are often recognisable by cracks in the mouth and crazing of the lips. Sometimes the tongue can turn a magenta red, suggesting a riboflavin deficiency. Finally, seborrhoeic dermatitis may appear on the ears, around the nose, between the nose and mouth and on the eyelids.
Lack of vitamin B3
Loss of appetite, headaches, dizziness, mood disorders, fatigue, digestive discomfort and vomiting can all be signs of niacin deficiency.
A dark red rash may also appear on the hands, feet, calves, neck or face.
Lack of vitamin B5
This very rare deficiency can cause fatigue, headaches, tingling and insomnia. Severe hair loss may also suggest a deficiency in B vitamins.
Lack of vitamin B6
Chapped lips, seborrhoeic dermatitis, a red tongue, tingling and numbness in the hands and feet may suggest symptoms of vitamin B6 deficiency.
Lack of vitamin B8
Brittle, fragile nails, acne, hair loss (alopecia), an oily scalp, dermatitis and skin problems are all common symptoms that can indicate a biotin deficiency. Recurrent conjunctivitis or muscle cramps can also indicate a lack of vitamin B8.
Lack of vitamin B9
Symptoms of vitamin B9 deficiency frequently include dizziness, paleness, headaches, shortness of breath and fatigue.
Lack of vitamin B12
Vitamin B12 deficiency can occur in people who do not eat animal products, and is more common in vegan and sometimes vegetarian diets. It can be recognised by paleness, frequent shortness of breath, difficulty concentrating and severe fatigue.