You may be trying to eat a healthy diet but not know whether you are getting the nutrients you need. Vitamin B-12 is found in a variety of animal-based products, iron is in meat, beans and leafy green vegetables, and you can get vitamin D from fortified foods, fatty fish and radiation from the sun. These nutrients are essential for good health, and if you have signs or symptoms of a deficiency, talk to a doctor to find out what you should do.
You need iron for healthy red blood cells, and a low intake may cause iron-deficiency anemia, according to the National Institutes of Health. Symptoms of anemia include fatigue, weakness, lethargy, shortness of breath and difficulty concentrating and learning. Low vitamin B-12 levels can result in another kind of anemia, called megaloblastic anemia. This condition results from abnormally large, immature, red blood cells, according to the Linus Pauling Institute Micronutrient Information Center, and symptoms are similar to iron-deficiency anemia.
You need vitamin D to absorb calcium from your food and use it to develop and maintain strong bones and teeth. Over time, inadequate vitamin D can lead to weak bones, such as rickets in children or osteomalacia in adults. You can get vitamin D from your diet, and radiation from the sun can cause your skin to make vitamin D, but you may be at risk for deficiency if you do not get adequate sun exposure, if you are an older adult or if you have darker skin.
An important symptom of low vitamin B-12 may be higher than normal levels of homocysteine in your blood, according to the Linus Pauling Institute Micronutrient Information Center. Homocysteine is a metabolic product found in your blood when you break down methionine, an amino acid, and high homocysteine levels increase your risk for heart disease. You need adequate amounts of vitamin B-12, folate and vitamin B-6 to reduce homocysteine, so if your levels are high, analyze your diet carefully to determine whether you might have a vitamin deficiency.
Since iron is essential for a healthy immune system, a symptom of low iron is a higher rate of infectious illnesses, according to the Linus Pauling Institute Micronutrient Information Center. Low iron status inhibits your body's ability to kill pathogens, or disease-causing bacteria, that can cause serious diseases such as malaria, tuberculosis or typhoid. Insufficient vitamin D may increase your risk for autoimmune diseases, such as type 1 diabetes or multiple sclerosis. Consult your doctor if you think you have an infection or autoimmune disease.
- National Institutes of Health: Dietary Supplement Fact Sheet: Iron
- National Institutes of Health: Dietary Supplement Fact Sheet: Vitamin B-12
- Linus Pauling Institute Micronutrient Information Center; Vitamin B-12; Jane Higdon; March 2003
- Linus Pauling Institute Micronutrient Information Center; Vitamin D; Jane Higdon; March 2004
- Linus Pauling Institute Micronutrient Information Center; Iron; Jane Higdon; January 2006