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I recently had what I thought was a case of severe chapped lips that extended to the corners of my mouth, where small, painful cracks developed. I was surprised to learn that the condition, called angular cheilitis, is actually the result of a vitamin B deficiency. I’d recently stopped taking my multivitamin (because it was upsetting my stomach) and believe that’s what brought it on.
Vitamin deficiency symptoms are as varied as they are common. They’ve been linked to depression and anxiety, fatigue, cognitive decline, and much more. A 2011 study found that 30 percent of Americans don’t get enough vitamin A and 70 percent don’t get enough vitamin D. Many more people are deficient in one or more of the B vitamins as well.
Fortunately, vitamin deficiency symptoms are often very easy to fix. Here’s a look at what you might experience if you’re deficient in vitamin A, B, or C—plus advice on what to do about it.
Vitamin A Deficiency Symptoms
Vitamin A really does improve your vision—it’s a key element in night vision. But that’s not all: it also plays a role in healthy skin, lungs, intestines, and the respiratory tract, and protects against infections.
In developed countries, deficiency is rare, but it is common among people who rely on rice as a staple food. It can also result from chronic diarrhea, celiac disease, cystic fibrosis, pancreatic disorders, or liver damage.
Vitamin A deficiency symptoms include:
- Night blindness (early) leading to full blindness 
- Dry eyes, skin, and other tissues 
- Increased infections 
- Thinning and ulceration of the cornea 
- Oval, triangular, or irregular foamy patches on the white of the eye
- Dry hair 
- Pruritis 
- Broken fingernails 
To treat vitamin A deficiency, a doctor will prescribe high doses of vitamin A, followed by lower doses until symptoms improve. It’s important to work with a physician if you suspect vitamin A deficiency, as high doses of vitamin A can be toxic.
The recommended daily allowance for vitamin A is 700 mcg for healthy women and 900 mcg for men. The upper tolerability limit (UTL) is 3000 mcg. The UTL, set by the Institutes of Medicine, is the highest amount of a nutrient that can be taken daily before adverse effects may occur.
Food sources of vitamin A include:
- Dark leafy greens
- Sweet potatoes
Vitamin B Deficiency Symptoms
Vitamin B refers to a collection of vitamins with different uses and deficiency symptoms. They include B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6, B12, folic acid, and biotin. While each B vitamin has specific effects, they work synergistically.
Vitamin B deficiency symptoms include:
- B1 (thiamine): fatigue and irritability. Beriberi results from severe deficiency and can affect the nerves, muscles, heart, and brain. 
- B2 (riboflavin): cracks in the corners of the mouth, scaly patches on the head 
- B3 (niacin): mental confusion and dementia, along with scaly skin, muscle weakness, and diarrhea,  memory impairment, disorientation, depression, mania, delirium, or paranoia 
- B5 (pantothenic acid): seizures, scaly rash, red tongue, cracks in the corners of the mouth, or a pins-and-needles sensation in the hands and feet 
- B12: Fatigue , anemia, paleness, weakness, shortness of breath, dizziness, tingling or loss of sensation in the hands and feet, muscle weakness, loss of reflexes, difficulty walking, confusion, and dementia 
- Folate/folic acid: fatigue, anemia, paleness, irritability, shortness of breath, and dizziness, red and sore tongue, a reduced sense of taste, weight loss, depression, neural tube defect in infants of folate-deficient mothers 
- Panic attacks, anxiety and depression. (Read more about vitamin B and depression here.)
To treat a vitamin B deficiency, it’s often simplest to take a vitamin B complex that contains all of the necessary components. You may want to supplement with additional B vitamins for certain conditions.
For example, for fatigue, try at least six weeks of a high-potency B complex supplement, along with an additional 2000 micrograms of sublingual (under the tongue) B12 every day. Be sure the form of B12 is methylcobalamin, which has the highest absorption. (Read more about treating fatigue with vitamin B here.)
The recommended daily allowances for healthy adults for the various vitamin Bs are as follows:
- B1 Thiamine: 1.2 mg for men, 1.1 mg for women, no UTL
- B2 (riboflavin): 1.3 mg for men, 1.1 mg for women, no UTL
- B3 (niacin): 16 mg men, 14 mg women, UTL 35 mg/day
- B5 (pantothenic acid): 5 mg men and women, no UTL
- B6: 1.3 mg men and women, no UTL
- B12. 2.4 mcg men and women, no UTL
- Folic acid: 400 mcg men and women, 1000 mcg/day
- Biotin: There is no RDA for biotin, but the adequate intakes is 30 mcg
The Recommended Dietary Allowance, established by the Food and Nutrition Board of the National Academy of Science, is the average daily dietary intake level that is sufficient to meet the nutrient requirement of 97 to 98 percent of healthy men or women of a certain age, and is based upon clinical evidence. If there is not enough evidence to establish an RDA, then an adequate intake value is used instead.
For food sources of the different members of the vitamin B family, see the vitamin deficiency symptoms chart.
Vitamin C Deficiency
While I’m pretty sure I’ll never personally have a vitamin C deficiency due to my excessive grapefruit and orange habit, it can happen. Vitamin C is water soluble, so any extra is excreted in urine and needs to be replaced. Vitamin C is credited with boosting immunity, but that’s not all it does. It helps heal wounds; repairs cartilage, bones, and teeth; and is an antioxidant.
Signs of deficiency include:
- Bleeding gums
- Lowered resistance to infection
- Slowed wound healing
- Dry, splitting hair
- Weight gain
- Dry skin
- Painful joints
- Weakened tooth enamel
Healthy men should get about 90 mg of vitamin C per day, while women need about 75 mg. If you smoke, though, add 35 mg per day.
Good food sources of vitamin C include: 
- Kiwi fruit
- Leafy greens
- Peppers, green and red
- Potatoes (sweet and white)
More Vitamin and Mineral Deficiency Symptoms
This is just a brief look at some of the vitamin deficiencies you may encounter. Don’t miss the following blogs, which look into a range of other deficiencies that can cause a host of problems.
Vitamin D deficiency is common and very damaging. Find out the 10 Vitamin D Deficiency Symptoms.
Calcium deficiency affects more than your bones. Learn 21 Calcium Deficiency Symptoms That Will Surprise You.
Magnesium deficiency is personally interesting to me: I found out that it was playing a role in my asthma. Find out what else it does here.
Iron deficiency is another common condition. Get a list of the symptoms (and best treatment) here.
Vitamins and Cancer
There has been media coverage of studies that allege that taking vitamins can cause cancer. The most oft-cited study looked at vitamin E and prostate cancer. Conversely, there have also been claims that certain vitamins can prevent or even treat cancer. But when you look at the research as a whole, there just isn’t enough evidence to defend either of these positions.
The confusion comes from a misunderstanding between nutrients and supplements. People who naturally eat a lot of foods that contain certain vitamins may demonstrate lower rates of certain types of cancer.
But taking very high doses of a single supplement doesn’t mean that the same results will be achieved. That’s why it’s always best to get your vitamins and minerals from food first.
Vitamins are an excellent way to augment—but never to replace—a healthy diet. The studies that have found higher rates of cancer with vitamin consumption are often using very high doses that are not recommended in the general population.
A good rule of thumb is to follow the Institute of Medicine’s (IOM) upper limits of tolerability for any vitamins or minerals, or to work closely with an integrative physician who can tailor a plan specifically for you.
Where to Start
For many people, a simple multivitamin is a great first step. Look for one that meets the recommended daily allowance of the vitamins listed in the vitamin deficiency chart.
Different brands have different levels of tolerability, so you may have to experiment to find one that you like. I recently tried one that made me very nauseated and my local vitamin shop owner suggested that I look for an alternative without iron. If you still suspect that you have specific deficiencies, then add individual supplements to your multivitamin.
Share Your Experience
Use the Comments section below to tell your fellow readers about your experiences—positive or negative—with vitamin supplements.
 J Neurol Neurosurg Psychiatry. 2004 Aug;75(8):1093-9.
 Baik HW, Russell RM (1999
 Alan Kristal, M.D., associate head, Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle; Durado Brooks, M.D., director, prostate and colorectal cancers, American Cancer Society; Feb. 21, 2014, Journal of the National Cancer Institute
This article, originally published in 2015, is regularly updated.