A recent study has highlighted the fact that biotin can alter some blood test results.
Biotin (Vitamin B7) is commonly used in high doses to boost hair growth. There is no good scientific evidence that it helps but there are plenty of patient reports of benefit.
Most people have taken the position that high dose Biotin may help and does no harm so, on balance, worth taking.
There is still no evidence of actual harm but, because biotin is used in laboratories as part of blood testing, High dose biotin can affect lab results.
How much is high dose. The recommended daily intake (RDI) of biotin is 30 mcg or 0.03mg. Doses used for hair growth are usually in the 1-10mg range. Doses as high as 1200mg are used by some people to boost their mitochondria and for multiple sclerosis.
The following test results (on the next page) may be affected:
- Thyroid. Biotin can make the thyroid look more active or less active than it truly is.
- TSH decrease
- T4 increase or decrease
- T3 increase
- Parathyroid hormone. Result is falsely lowered.
- LH and FSH falsely lowered.
- Testosterone and DHEAS falsely elevated.
- Serum hCG falsely lowered, possible false negative pregnancy test.
- Oestrogen and Progesterone falsely elevated.
- Prolactin falsely lowered.
- Cortisol falsely elevated.
- Vitamin D falsely elevated.
- Vitamin B12.
- Prostate Specific Antigen.
- Troponin falsely lowered.
The falsely low Troponin result has lead to a tragic death in the USA. A raised troponin is one of the tests used to diagnose a heart attack. A patient was sent home following a normal result and subsequently died at home. A rare but tragic event.
Most relevant is the effect on hormone results, especially thyroid.
What to do? People taking less than 100mg of biotin a day can clear their system by stopping biotin for 48 hours before a blood test. I think it is worth doing this at least once to check whether you have this issue.