7. Vitamin D
According to NHANES data, about 8.1% of Americans are vitamin D deficient — a number that may seem low if you test your patients regularly for this vitamin level. Of course, this will also depend on where you live and how outdoorsy your patients are.
“The most common vitamin deficiency we see is Vitamin D,” says Dr. John A. Robinson, NMD. “We test for it consistently and it is almost always low or suboptimal. A major reason is that most people do not go out into the sun long enough to generate Vitamin D. And if they do supplement with Vitamin D, it is often too low of a dose to be effective.”
There is also the factor that sunscreen is recommended at all times when a person is outdoors — even if it’s overcast on that particular day. Sunscreen blocks vitamin D production in the body, which increases the possibility that a given person will have a vitamin D deficiency, especially if they’re adhering to these guidelines.
Robinson says that vitamin D is the deficiency he looks out for the most, because not only is it crucial for multiple functions within the body, it’s also “easy to test for it and easy to correct.”
“Vitamin D operates like a hormone in your body and is needed for proper immune function,” says Robinson. Vitamin D plays a major role in “pain regulation, brain function, mood balancing, weight loss, insulin and blood sugar control, and much more.”
In fact, research has shown that adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis. The reason for this is that vitamin D is crucial for calcium absorption.
Vitamin D deficiency is often missed (unless tested for) because its symptoms share so many similarities with other diagnoses. Symptoms include:
- Fatigue
- Muscle weakness, aches, or cramps
- Bone pain
- Mood changes
- Frequent illness
- Skin problems
It’s difficult to get all the vitamin D the body needs through food alone, but there are some foods that are good sources of vitamin D that can be incorporated into a healthy diet:
- Cod liver oil
- Salmon
- Tuna
- Foods fortified with vitamin D, such as orange juice, milk, yogurt, and cereal
“While ‘food first’ is a general rule, sometimes supplementation is warranted based on each individual’s needs and abilities,” says Manju Karkare, MS RDN LDN CLT FAND. “For example, vitamin D supplementation is very easy, inexpensive and much better than sun exposure for someone who may have genetic predisposition to skin cancer. Plus, sunscreen is essential for all of us. If adequate intake is not possible for any intolerance to good food sources, that is also a good reason to use to supplement.”
8. Folate/Folic Acid
According to NHANES data, having a folate deficiency is rare in the United States, with numbers coming in at under 1%. The number of people (especially women) with a folate deficiency or insufficiency decreased dramatically across multiple races and ethnicities between 1998 and 2006 because of a public health push to ensure that women who were pregnant (or trying to become pregnant) were getting enough folate in their diets, or supplementing with folic acid.
In 1998, FDA began requiring that folic acid be added to all enriched cereals and grains. The reason for this is that folate plays a major role in cell division and growth, making it vital for pregnant women and infants. Research has shown time and time again that adequate folate may reduce a woman’s risk of having a child with a brain or spinal cord birth defect.
Symptoms of a folate deficiency include:
- Megaloblastic anemia
- Fatigue
- Weakness
- Shortness of breath
- Trouble concentrating
- Headaches
- Heart palpitations
- Open sores inside the mouth
- Changing the color of hair, fingernails, or skin
- Mental and emotional disorders
- Agitation and irritability
In addition to FDA’s push for adding folic acid to fortified foods, this vitamin is found in many food sources, such as:
- Cantaloupe
- Citrus and tropical fruits (like bananas and mangos)
- Vegetables (especially asparagus, brussels sprouts, and leafy greens)
- Beans & legumes
- Nuts & seeds
- Enriched grains, bread and pasta
- Fortified breakfast cereals
NHANES data, however, does not take into account the latest genetic research showing that a large part of the population (40-60%) has a genetic variant that may significantly affect the conversion of folic acid or folate they consume into the active methylfolate the body can use. Why is this important? Because methylation is required for many biochemical reactions that regulate the activity of our cardiovascular, neurological, reproductive, and detoxification systems and activated methylfolate is needed for the methylation process.
If enough active methylfolate is present, the methylation cycle will work efficiently. But folate from the diet or folic acid from supplements must be converted to the active form before it can be used in the body in the methylation cycle.
The best supplement brands put only active methylfolate (5-MTHF) in their multivitamins instead of folic acid because we now know that many people cannot efficiently convert folic acid to the methylfolate the body needs.