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Brittle nail because if biotin deficincey also do continue to take biotin dose.
Aging may cause brittle nail.
Avoid long time use of nail polish...
Avoid too moisture environment and swimming like activity....
Dehydration cause brittle nail.
so rehydrate your body by taking more water and diet.
Some other vitamines like iron ,
folic acid ,vitamine c may cause brittle nail.
Eat citrus fruits and green vegetables. ..
Menopause may cause brittle nail because of
oestrogen deficiency. Try to treat the menopause condtion.
Hypothyroidism may cause brittle nail .Do thyroid function test .
You can use following home care like ......
coconut oil is provide moisture to nail so apply warm coconut oil over nail for 5 minutes.
Vitamine E oil or olive oil is also helpful.Massage of nail is helpful.
Avoid moisture condition.
Avoid nail irritant.
Take care.
Thank you very much.