Vitamins, Supplements and Deficiency Treatment

Name: Vitamins, Supplements and Deficiency Treatment
Creator: Dr Zamiel Hussain

Vitamins and mineral supplements are widely used for energy, immunity, hair health, mood, and general wellbeing. However, supplementation is not always necessary and may not address the underlying cause of symptoms.

In primary care, treatment decisions are guided by:

Symptoms
Diet and lifestyle
Medical history
Medication use
Blood test results where appropriate

Some deficiencies are common and well recognised. Others are rare. Safe treatment depends on identifying whether a deficiency is likely before starting long-term supplementation.

These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help, please book an appointment with one of our GP’s.

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When Supplements May Be Appropriate

Supplements may be considered when there is:

Confirmed deficiency on blood testing
Increased physiological demand (pregnancy, growth, ageing)
Restricted diet
Certain medical conditions affecting absorption
Medication-induced depletion

Routine supplementation without indication is not always beneficial and may sometimes cause harm at high doses.

Vitamin D

Vitamin D deficiency is common in the UK, particularly in winter months and in people with limited sun exposure.

Low vitamin D levels may be associated with:

Fatigue
Muscle aches
Bone pain
Low mood in some cases

Vitamin D supplementation may be recommended when deficiency is confirmed or strongly suspected.

Very high doses taken long term without monitoring may cause harm.

Learn more: Vitamin D Test

Iron and Iron Deficiency

Iron deficiency is a common cause of fatigue, particularly in:

People with heavy menstrual bleeding
Pregnancy
Certain gastrointestinal conditions
Restricted diets

Symptoms may include:

Fatigue
Hair thinning
Shortness of breath on exertion
Pale skin

Iron supplementation should ideally follow blood testing to confirm deficiency.

Iron can cause constipation, nausea, and dark stools.

Learn more:

Vitamin B12

Vitamin B12 deficiency may occur in:

Vegans or strict vegetarians
People with absorption disorders
Long-term metformin use
Certain gastric conditions

Symptoms may include:

Fatigue
Tingling or numbness
Memory difficulty
Balance issues

Treatment may involve oral supplementation or injections depending on cause and severity.

Long-term self-supplementation without testing may mask underlying conditions.

Folate (Folic Acid)

Folate deficiency may occur with:

Poor dietary intake
Alcohol excess
Certain medications
Malabsorption

Folate is particularly important in early pregnancy.

Folate supplementation should not replace investigation of underlying causes where deficiency is identified.

💡 Folic acid supplementation is important in early pregnancy. Read more: Contraception and Family Planning.

Magnesium

Magnesium is often marketed for muscle cramps, sleep, and stress.

True magnesium deficiency is relatively uncommon in otherwise healthy individuals.

Supplementation may be considered in selected cases but excessive intake can cause diarrhoea and gastrointestinal upset.

Multivitamins

Multivitamins may help address minor dietary gaps but do not replace a balanced diet.

High-dose combinations are not necessarily more effective and may contain unnecessary ingredients.

Supplements and Fatigue

Fatigue is one of the most common reasons people consider supplements.

However, fatigue can be caused by:

Sleep disturbance
Thyroid dysfunction
Anaemia
Chronic disease
Mental health conditions
Medication side effects

Blind supplementation may delay correct diagnosis.

If fatigue is persistent, medical assessment and targeted blood testing are often more helpful than multiple supplements.

🩸 Explore blood testing with AccessGP for convenient comprehensive options.

Supplements and Hair Loss

Hair thinning may be associated with:

Iron deficiency
Thyroid dysfunction
Hormonal change
Stress

Biotin and other “hair vitamins” are commonly marketed but are not universally indicated.

Blood testing may help guide treatment. Learn more about blood tests.

Supplements and Immune Health

There is ongoing public interest in supplements for immune support.

Vitamin D and zinc are commonly discussed, but supplementation is most beneficial when deficiency exists.

Balanced diet, sleep, vaccination, and chronic disease control remain central to immune health.

Risks of Over-Supplementation

High-dose supplementation may cause harm, including:

Vitamin D toxicity
Iron overload
Masking of B12 deficiency with folate
Drug interactions

Supplements can interact with prescribed medicines.

Examples include:

Iron reducing absorption of some medications
Vitamin K interacting with blood thinners
High-dose biotin interfering with certain blood test results

Individual review is important before starting long-term high-dose supplementation.

Frequently Asked Questions

1. Should I take vitamin supplements if I feel tired?

Not always. Fatigue has many possible causes. Blood testing may help identify whether a vitamin deficiency is present before starting supplements.

2. Is vitamin D supplementation safe?

Vitamin D is commonly supplemented in the UK, particularly in winter. However, very high doses taken long term without monitoring can cause harm.

3. Can taking too many supplements be harmful?

Yes. High-dose supplements can cause side effects, interact with medications, or mask underlying conditions. Review is advisable before long-term use.