Silent Symptoms of Vitamin Deficiencies That Show Up in Hair, Nails, and Skin

Hair thinning, brittle nails, cracked lips, and dull skin are often brushed off as cosmetic concerns. In many cases, these changes are quiet warning signs of vitamin and mineral deficiencies that signal the body is missing key nutrients needed for everyday health.

A well-balanced diet supplies the body with vitamins and minerals needed for energy, repair, and overall function. When certain nutrients are missing, the body often sends subtle signals before more serious health issues develop. Hair, nails, and skin are among the first areas to reflect internal deficiencies.

Recognizing these early signs can help address nutritional gaps before they worsen. Below are common symptoms of vitamin and mineral deficiencies and the nutrients most often linked to them.

Brittle Nails and Thinning Hair

Brittle nails and weak, thinning hair are frequently associated with a lack of biotin, also known as vitamin B7. Biotin plays a key role in converting food into energy and supporting the health of hair and nails. When levels are low, hair may split or shed more easily, while nails may peel or break.

One lesser-known cause of biotin deficiency is consuming raw egg whites. Raw egg whites contain avidin, a protein that interferes with biotin absorption. Cooking eggs neutralizes this effect.

Foods rich in biotin include eggs, fish, meat, dairy products, nuts, seeds, whole grains, spinach, broccoli, bananas, cauliflower, sweet potatoes, and nutritional yeast.

Cracks at the Corners of the Mouth

Painful cracks or sores at the corners of the mouth can point to deficiencies in iron or B vitamins, particularly thiamine (vitamin B1), riboflavin (vitamin B2), and pyridoxine (vitamin B6). These nutrients support skin health, red blood cell production, and energy metabolism.

Iron-rich foods include red meat, poultry, fish, dark leafy greens, legumes, nuts, seeds, and whole grains. B vitamins are commonly found in whole grains, dairy products, meat, eggs, and fortified cereals.

Poor Night Vision

Difficulty seeing in low-light conditions is a classic symptom of vitamin A deficiency. Vitamin A supports healthy vision, immune function, and skin integrity. While vitamin A deficiency is uncommon in developed countries, it can still occur with highly restrictive diets.

To maintain adequate vitamin A levels, include dairy products, eggs, fish, dark leafy greens, and yellow-orange vegetables such as carrots, squash, and sweet potatoes.

Numb or Tingling Fingers

Numbness or tingling in the fingers can be a sign of low calcium levels. Calcium is essential for maintaining strong bones, supporting muscle movement, and regulating nerve signaling. Severe deficiency may also affect heart rhythm.

Calcium is found in dairy products such as milk and yogurt, as well as dark leafy greens like kale and broccoli. Fortified plant-based milks can also be a helpful source.

Fatigue and Mood Changes

Persistent fatigue, mood shifts, and bone discomfort may indicate a vitamin D deficiency. Vitamin D plays a critical role in bone health, immune function, and muscle strength. The body produces vitamin D when the skin is exposed to sunlight.

Spending time outdoors regularly can help maintain healthy levels, along with consuming foods such as fortified dairy products, eggs, and fatty fish.

Hair, skin, and nail changes often reflect what is happening inside the body. While these symptoms may seem minor, they can signal important nutritional gaps. Maintaining a varied, nutrient-rich diet and paying attention to early warning signs can support long-term health and help prevent more serious deficiencies over time.