Your hair and nails may be signalling hidden gaps in your diet: Harvard trained gut doctor explains the subtle signs to watch for

Harvard trained gastroenterologist Dr Saurabh Sethi has shared a set of everyday physical cues that may be quietly warning you about nutritional gaps. In a recent Instagram video, the San Francisco Bay Area based specialist highlighted five subtle signs that often slip under the radar but can offer important clues about what the body is missing. The insights were shared in a short explainer posted on his official account, where he regularly breaks down complex health topics for the public.

When your nails, eyes or joints speak up

According to the video, brittle nails are among the earliest markers that something may be off. Dr Sethi explained that weak or easily breaking nails can indicate low protein or iron levels, and in some cases, dehydration. He added that twitching around the eyelids or in the limbs is another sign to watch for, usually pointing to magnesium deficiency, a mineral essential for muscle and nerve regulation.

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A post shared by Saurabh Sethi MD MPH | Gastroenterologist (@doctor.sethi)

Popping joints and graying strands

The doctor noted that clicking joints or unexpected hip pops can be a silent hint of low vitamin D or calcium. These nutrients play a crucial role in maintaining bone and joint health, and early symptoms often emerge long before any serious concern develops. He also mentioned that premature graying may have less to do with genetics than many assume. Low vitamin B12 or copper levels, he said, are frequently behind early loss of hair pigmentation.

Bruising too easily? Your vitamins may be dipping

In the same video, Dr Sethi pointed out a fifth sign that often goes unnoticed. People who find bruises appearing on their skin without significant impact may be running low on vitamin C or vitamin K, both of which support blood vessel strength and healing.

Dr Sethi, who trained at AIIMS, Harvard, and Stanford, is known for translating medical knowledge into accessible advice. As a board certified gastroenterologist and hepatologist, he brings clinical experience from his work in advanced interventional endoscopy to his digital platforms, where thousands follow his simplified breakdowns of gut health and nutrition.