Dietary Fatty Acids

Dietary fatty acids tests measure the types and balance of fats in your blood—especially omega-3 (EPA, DHA) and omega-6 (linoleic acid/arachidonic acid)—to give an objective view of heart, brain, eye, and metabolic health support. Because food logs and memories are imperfect, blood testing offers a clear, trackable baseline, helps you and your clinician fine-tune diet and supplements, and shows whether changes are taking hold.

A proactive plan often starts with the Omega-3 Index and the omega-6:omega-3 ratio, then adds targeted markers such as EPA%DHA%DPA%AA%LA%, the AA:EPA ratio, and trans fatty acids. Choose red blood cell (RBC) membrane testing for longer-term status (≈8–12 weeks) or plasma/phospholipid testing for shorter-term intake (days–weeks). These labs support screeningoptimization, and monitoring, but they do not replace medical care, cardiovascular risk assessment, or nutrition counseling.

Signs, Symptoms & Related Situations

  • Heart & metabolic context: high triglycerides, low HDL, central weight gain, family history of early heart disease

  • Brain/eye & performance: low mood, brain fog, attention changes, dry eyes, exercise recovery goals

  • Inflammation cues: joint stiffness, frequent soreness, elevated hs-CRP in the past

  • Diet patterns: little or no seafood, plant-based eating without marine omega-3s, high intake of refined seed oils, heavy fried/processed foods

  • Life stages: pregnancy planning, breastfeeding, healthy aging goals

  • Medication/supplement changes: starting or stopping fish-oil, algal oil, borage/evening primrose, or high-dose omega-6 supplements

  • Urgent care now: chest pain, shortness of breath, neurological deficits, or severe allergic reactions require immediate medical attention

Symptoms and risks should be reviewed by a qualified clinician.

Why These Tests Matter

What testing can do

  • Quantify status of key fatty acids (EPA, DHA, AA, LA) and your Omega-3 Index

  • Assess balance using omega-6:omega-3 and AA:EPA ratios that many clinicians use to discuss inflammatory tone

  • Track trends after diet/supplement adjustments and support heart, brain, and eye health goals

What testing cannot do

  • Diagnose or treat disease by itself, or predict events with certainty

  • Substitute for a full cardiovascular risk evaluation (e.g., ApoB, Lp(a), blood pressure, glucose)

  • Provide dosing or therapy advice—discuss results with your clinician or dietitian

What These Tests Measure (at a glance)

  • Omega-3 Index (RBC EPA+DHA %): longer-term omega-3 status; higher values are generally viewed as more favorable for cardiometabolic support. Ranges/targets vary by lab; compare on the same method over time.

  • EPA% / DHA% / DPA%: individual omega-3 contributors; DHA relates to brain/retina membranes, EPA often to inflammatory tone.

  • Omega-6:Omega-3 Ratio: balance marker; lower ratios typically indicate more omega-3 relative to omega-6.

  • AA:EPA Ratio: another inflammatory-balance signal; lower values indicate proportionally more omega-3 (context-dependent).

  • AA% (Arachidonic Acid) / LA% (Linoleic Acid): major omega-6 fatty acids; essential for health but out-of-balance intakes may track with inflammatory tone.

  • ALA% (Alpha-linolenic Acid): plant omega-3; conversion to EPA/DHA is limited in many people.

  • Trans Fatty Acids (%): industrial trans fats and some ruminant trans fats; lower is better.

  • Specimen types: RBC membrane reflects 8–12 week intake; plasma/phospholipid reflects recent intake (days–weeks).

Quick Build Guide

Goal / Scenario Start with Add if needed
Wellness baseline Omega-3 Index (RBC) • Omega-6:Omega-3 ratio EPA% • DHA% • AA% • AA:EPA • Trans fats
Heart health optimization Omega-3 Index • Omega-6:Omega-3 ApoB • Lp(a) • Lipid panel • hs-CRP
Brain/eye support or low seafood intake Omega-3 Index • DHA% EPA% • ALA%
Inflammation/joint cues AA:EPA • Omega-6:Omega-3 Omega-3 Index • hs-CRP
Plant-based diets Omega-3 Index • ALA% EPA% • DHA% • Omega-6:Omega-3
Pregnancy planning Omega-3 Index (DHA emphasis) Ferritin • Vitamin D (general wellness context)
Follow-up after changes Same test/method as baseline Recheck in 8–12 weeks for RBC-based panels

How the Testing Process Works

  1. Choose the specimen type: pick RBC membrane for long-term status or plasma/phospholipid for shorter-term changes.

  2. Prepare as directed: fasting is usually not required unless your order includes standard lipids. Follow any kit instructions; list all supplements and oils on your order.

  3. Provide a blood sample: standard venous draw (some panels may use dried blood spot—follow instructions).

  4. Get secure results: values and ratios post to your account, typically within a few days.

  5. Review & iterate: discuss results with your clinician/dietitian; adjust diet/supplements and retest on the same method to track progress.

Interpreting Results (General Guidance)

  • Omega-3 Index low/borderline: consider diet/supplement changes; retest in 8–12 weeks (RBC method) to gauge the new steady state.

  • Omega-6:Omega-3 ratio high: suggests proportionally lower omega-3 intake; interpret alongside individual EPA/DHA%.

  • AA:EPA high: may indicate a more pro-inflammatory balance; view with hs-CRP and clinical context.

  • Trans fats detectable/high: reduce sources of industrial trans fats; confirm with your clinician/dietitian.

  • Method matters: compare like-to-like (same assay and specimen type) over time. Reference ranges and desirable zones vary by lab.

Choosing Panels vs. Individual Tests

  • Comprehensive balance: Omega-3 Index • Omega-6:Omega-3 ratio • AA:EPA • EPA% • DHA% • AA% • LA% • Trans fats

  • Targeted checks:

    • Omega-3 emphasis: Omega-3 Index • DHA% • EPA%

    • Inflammatory tone: AA:EPA • Omega-6:Omega-3 • hs-CRP

    • Diet pattern review (plant-based/low seafood): Omega-3 Index • ALA% • DHA%
      Choose bundled panels for an all-in-one snapshot; add single markers to answer specific questions.

FAQs

Do I need to fast for fatty acid testing?
Usually no—fast only if your order also includes fasting lipids. Follow your panel’s instructions.

RBC vs. plasma—what’s the difference?
RBC reflects 8–12 weeks of intake (long-term status). Plasma reflects recent intake (days–weeks).

Should I stop fish oil before testing?
Follow the instructions provided. Note that RBC measures are less affected by a single recent dose than plasma tests.

How soon will diet changes show up?
With RBC panels, allow 8–12 weeks to see the full effect. Plasma panels change faster.

Can these tests diagnose heart disease?
No. They quantify fatty acid status and balance; they don’t diagnose. Pair with a full risk review.

What’s a “good” Omega-3 Index or ratio?
Labs use different ranges and desirable zones. Use your report’s guide and track trends on the same method.

Do plant oils cover omega-3 needs?
ALA from plants converts poorly to EPA/DHA in many people. Testing clarifies your actual status.

Related Categories & Key Tests

  • Upward: Nutrition & Wellness Tests Hub

  • Sideways: All Vitamin & Mineral Deficiency Tests • Heart & Cardiovascular Risk • Cholesterol Tests • Inflammation Tests • Brain Health • Diabetes Health

  • Key Tests (downward): Omega-3 Index (RBC EPA+DHA %) • Omega-6:Omega-3 Ratio • AA:EPA Ratio • EPA% • DHA% • DPA% • ALA% • AA% • LA% • Trans Fatty Acids % • hs-CRP • ApoB • Lp(a) • Lipid Panel

References

  • American Heart Association — Science advisories on omega-3 fatty acids and cardiovascular health.
  • NIH Office of Dietary Supplements — Omega-3 and Omega-6 Fatty Acids fact sheets.
  • Academy of Nutrition and Dietetics — Position papers on dietary fats and health.
  • American College of Cardiology/American Heart Association — Cholesterol and risk assessment guidelines.
  • Clinical reviews on Omega-3 Index, omega-6:omega-3 balance, and AA:EPA interpretation.
  • Ophthalmology and neurology reviews on DHA in retinal and brain membranes.

Available Tests & Panels

Your Dietary Fatty Acids Tests menu is pre-populated in the Ulta Lab Tests system. Start with the Omega-3 Index and omega-6:omega-3 ratio, then use filters to add EPA/DHA/DPAAA/LAAA:EPA, and trans fats. Follow collection instructions and review results with your clinician or dietitian to fine-tune your plan and set a retesting interval.

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The Omega-3 and Omega-6 Fatty Acids Test measures essential fatty acids, including EPA, DHA, and arachidonic acid, to assess balance between omega-3 and omega-6 in the blood. This ratio is linked to heart health, inflammation, brain function, and metabolic wellness. Doctors use this test to evaluate diet quality, detect deficiencies or excess, and guide nutrition or supplement plans that support cardiovascular, cognitive, and overall long-term health.

Also Known As: OmegaCheck® Test

The Very Long Chain Fatty Acids (VLCFA) Test measures C22:0, C24:0, C26:0 and ratios (C24/C22, C26/C22), with phytanic and pristanic acids, by GC/MS to assess peroxisomal function. Abnormal VLCFAs support evaluation of X-linked adrenoleukodystrophy and Zellweger spectrum disorders, informing diagnosis of peroxisomal and neuro-metabolic disease in the right clinical context.

Blood
Blood Draw

The Beta-Hydroxybutyrate Test measures levels of beta-hydroxybutyrate, the primary ketone body in the blood, to assess ketosis and detect ketoacidosis. Elevated BHB is commonly associated with diabetic ketoacidosis, prolonged fasting, alcohol-related ketosis, or metabolic disorders. This test helps monitor ketone production, evaluate metabolic health, and distinguish between nutritional ketosis and pathological states.

Blood
Blood Draw
Also Known As: BHB Test

The Nonesterified Fatty Acids Test measures circulating free fatty acids, important indicators of lipid metabolism and energy balance. Abnormal levels may signal insulin resistance, diabetes, obesity, or metabolic syndrome. This test supports evaluation of cardiovascular risk, liver function, and disorders related to fat mobilization, helping providers assess how the body regulates fat breakdown and energy use.

Blood
Blood Draw
Also Known As: Free Fatty Acids Test

Blood
Blood Draw

The Comprehensive Fatty Acid Profile (C8–C26) analyzes 40+ fatty acids in serum—including medium, long, and very long chain species—to evaluate mitochondrial β-oxidation, peroxisomal disorders, essential fatty acid deficiency, or nutritional status. Abnormal patterns (e.g. elevated VLCFAs, altered w3/w6 ratios) help detect metabolic or peroxisomal defects and guide dietary or therapeutic interventions.

Blood
Blood Draw
Also Known As: Comprehensive Fatty Acid Test, Fatty Acids C8-C26 Test

A dietary fatty acid deficiency is rare. But people who suffer from it could experience debilitating effects.

However, it can be difficult to determine whether you actually have it or not. After all, the symptoms could be indicators of other conditions.

The chances are that if you are reading this page, you have a good reason for suspecting dietary fatty acid deficiency.

If that’s the case, our service at Ulta Lab Tests provides plenty of lab tests to screen for abnormal fatty acid levels along with many other dietary deficiencies.

But first, you might want to understand what this condition is and whether you have reason to be concerned.

So, keep reading to learn about what a dietary fatty acid deficiency is. This article will cover a general overview of dietary fatty acid deficiency and what tests can confirm or deny this condition.

What Is A Fatty Acid?

Before answering this question, it's important to understand what a fatty acid is in the first place. To start, fatty acids are energy storage units that makeup components of cell membranes. They're essential for the composition of white blood cells, red blood cells, plasma phosphatidylcholine, and tissue cells.

The body obtains fatty acids by consuming dietary fat. It's impossible for the body to produce its own fatty acids, which is why it's integral that individuals ensure an adequate intake of fatty acids.

There are only two fatty acids that are considered essential for the human body. These essential fatty acids are:

  • Alpha-linolenic acid (omega-3 fatty acid)
  • Linoleic acid (omega-6 fatty acid)

Other fatty acids are considered "conditionally" essential, meaning they may be essential for individuals with specific disease/developmental conditions.

Why are Essential Fatty Acids Important?

Essential fatty acid intake is exactly that - essential. The body needs to ingest enough dietary fat in order to perform numerous important bodily functions. Some of these functions include:

  • Energy storage
  • Skin/hair/eye health
  • Bone/joint health
  • Neurological health
  • Eliminating risk factors for heart disease
  • Mental health

There are many more benefits than the ones listed above. Either way, a proper intake of essential fatty acids isn't simply supplementary to your health. It's absolutely necessary.

What Is A Dietary Fatty Acids Deficiency?

A dietary fatty acids deficiency can also be referred to as essential fatty acids deficiency (EFAD). Either way, as the condition's name indicates, it refers to an individual's lack of adequate fatty acids levels. Most likely, this means that they're lacking in alpha-linolenic acid or linoleic acid levels.

It's a rare condition, both in children and in adults. EFAD is a fairly rare condition in the US, and is caused by inadequate dietary fat intake. It is also more common for there to be a deficiency in EPA and DHA, both of which are omega-3 fatty acids.

What Are the Causes of Dietary Fatty Acids Deficiency?

Once again, this condition is caused by an individual's lack of adequate dietary fat intake. Adequate dietary fat intake can usually be ensured by eating proper amounts of the following foods:

  • Cooking oils
  • Nuts
  • Seeds
  • Animal fat
  • Fish oil

Eating whole foods is the most ideal way to consume dietary fat. But many individuals take omega-3 supplements, such as fish oil or vegan omega-3 supplements, to boost their otherwise inadequate dietary fat intake. Studies even indicate a link between fewer heart disease deaths and boosted omega-3 fat intake.

What Are the Risk Factors for Dietary Fatty Acids Deficiency?

Since there tends to be a great number of fatty food sources available in the US, EFAD is fairly uncommon. However, individuals can also develop this condition through low-fat/fat-free diets. For them, simply increasing their dietary fat intake may be enough to regulate essential fatty acid levels.

Those at the end-stage of liver disease also suffer from EFAD. This condition is part of a host of other malnutrition problems sufferers of liver disease may experience.

There are certain populations that might be more at risk for EFAD, whether that be because of developmental and/or environmental concerns. Such populations may suffer from conditions such as:

  • Chronic malnutrition
  • Fat malabsorption conditions
  • Acrodermatitis enteropathica
  • Sjogren-Larsson syndrome

What Are the Signs and Symptoms of Dietary Fatty Acids Deficiency?

Essential fatty acid deficiency can be manifested through several signs and symptoms. Some of these indications include:

  • Dry, scaly rash
  • Anemia
  • Slowed growth rate
  • Alopecia
  • Slowed learning behavior
  • Increased frequency of stools

Which Lab Tests Screen, Diagnose, and Monitor for Dietary Fatty Acids Deficiencies?

At Ulta Lab Tests, we offer an omega-6 and omega-3 test to screen for deficiencies in Omega-3 and -6 fatty acids and general dietary fatty acid lab tests to test for an overall dietary fatty acids deficiency.

The omega-3 and -6 fatty acids lab test is conducted as follows:

  1. Patients will get their blood drawn to provide a plasma sample
  2. The plasma is then tested for omega-3 and omega-6 levels
  3. If omega-3/omega-6 levels are inadequate, then the patient is diagnosed with deficiencies in the fatty acids

Benefits of Lab Testing With Ulta Lab Tests for Dietary Fatty Acid Deficiency

Ulta Lab Tests offers tests that are highly accurate and reliable, so you can make informed decisions about your health. Here are a few great things to love about Ulta Lab Tests:

  • You'll get secure and confidential results
  • You don't need health insurance
  • You don't need a physician's referral
  • You'll get affordable pricing
  • We offer a 100% satisfaction guarantee

Order your omega-3 and omega-6 fatty acids lab test today to see if you have a dietary fatty acid deficiency. Afterward, your test results will be provided to you securely and confidentially online in 24 to 48 hours for most tests.

So, take control of your health with Ulta Lab Tests today!