Although the best way to tell if your not absorbing nutrients from your diet is to get a blood test to see what you are lacking, these are great ways to check in with your body for signs.
Check your skin, scalp and eyes for dryness and itchiness. Also check to see if your lips are dry and cracked. A lack of moisture in your skin may indicate low vitamin A or vitamin E levels. These vitamins also aid skin healing. Check your skin for slow-healing wounds. Look for flakiness and dandruff in your scalp; this may indicate a deficiency of vitamin A, vitamin B6 or the mineral zinc.
Inspect your tongue and gums. Canker sores or a sore tongue can indicate low levels of vitamin B2, vitamin B3 or vitamin B12. Tender, bruised or bleeding gums may be due to a deficiency of vitamin C.
Observe the inner lining of your eye, by gently pulling your lower lid downwards. If the lining appears pale and white rather than pink, you may have an iron deficiency. This mineral is important for red blood cell production, and a deficiency can lead to low energy, tiredness and dizziness.
Examine your neck for a bump or bulge at the front center, close to where your larynx lies. Also check for bloating, weight gain, fatigue and low energy levels.This may indicate a deficiency of the mineral iodine, which is found in seafood and added to salt. Iodine is needed for thyroid hormone production, which is important for normal metabolism levels.
Examine your fingernails closely. There are several signs of mineral and vitamin deficiencies that affect the fingernails. If your nails are thin, brittle and easy to split, you may have low levels of magnesium or copper. If you have white spots, you may have a zinc or calcium deficiency. Spooned nails indicate low iron or vitamin B12 levels.