Brief Answer:
Please refer below

Detailed Answer:
Hi
Thanks for your query.

You have not mentioned the clinical scenario. Hence I will assume that it is just to prevent illnesses.

First, you need to get adequate intake of vitamins and minerals. Especially, iron, folate, zinc, selenium, vitamin C and D. Adequately taking fruits, vegetables, meat, fish, nuts, milk products will provide these. Get enough sun exposure, which generates vitamin D. Consider taking trumeric extracts as it contains curcumin which has many health benefits and protects egainst cancer.

get regular exercises, apart from having many health benefits, it also improves immunity.

And last but not the least, do yoga or similar exercises. From time immemorial, they have boosted immunity.

hope this helps.
Regards

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