For four years, I did everything right.
I tried keto. I tried intermittent fasting. I went gluten-free. I hired a personal trainer. I cut alcohol completely. I tracked every calorie in MyFitnessPal with obsessive precision.
And I gained twelve more pounds.
The fatigue was the worst part. Not normal tired — the kind where you wake up after eight hours of sleep and immediately need to sit down. Combined with anxiety that had slowly crept into every corner of my life: waking up at 3am with a racing heart, constant low-level dread, brain fog so thick I couldn’t remember what I walked into a room for.
Every doctor told me the same thing: eat less, move more, consider therapy for the anxiety. I was dismissed as someone who wasn’t trying hard enough.
Then a new doctor ran a comprehensive blood panel — not just the standard cholesterol and glucose — and within a week, we had four clear answers to what had been years of mystery. None of them had anything to do with willpower.
The 4 Things My Blood Panel Revealed
1. Severely Low Vitamin D (17 ng/mL — the normal range is 40–80)
Vitamin D isn’t just about bones. It functions as a hormone that regulates mood, immune function, insulin sensitivity, and metabolic rate. At a level of 17, my body was effectively running in emergency mode.
The research is unambiguous: vitamin D deficiency is directly linked to weight gain, depression, fatigue, and anxiety. A meta-analysis of 41 studies found that people with the lowest vitamin D levels had a 64% higher risk of depression. A separate study in the European Journal of Nutrition found that vitamin D deficiency was associated with significantly higher rates of obesity and metabolic dysfunction.
Most standard lab panels don’t check vitamin D levels unless you specifically request it. Ask for a 25-hydroxy vitamin D test (25(OH)D) by name.
2. Subclinical Hypothyroidism (TSH of 4.8 — most labs flag nothing below 4.5, but optimal is 1–2)
The thyroid gland controls your metabolic rate — how fast your body converts food into energy. Even “subclinical” thyroid dysfunction (where numbers are technically within “normal” lab ranges but not optimal) can cause:
- Weight gain and inability to lose weight despite caloric restriction
- Persistent fatigue and low energy
- Anxiety, depression, and mood swings
- Brain fog and poor memory
- Cold intolerance, hair loss, constipation
Here’s the problem: the “normal” TSH range used by most labs is 0.4–4.5 mIU/L. But the American Thyroid Association and many endocrinologists consider 1–2 mIU/L to be optimal. A TSH of 4.8 placed me technically outside even the conventional range — but my previous doctor hadn’t flagged it because it was “borderline.”
If you have unexplained weight gain, fatigue, and anxiety, request a full thyroid panel: TSH, Free T3, Free T4, and thyroid antibodies (TPO and TGAb). A standard “thyroid check” often only measures TSH, missing critical information.
3. High Fasting Insulin (28 mIU/L — optimal is below 10)
My fasting blood glucose was 94 — completely normal. So no doctor had ever flagged my blood sugar. But my fasting insulin was nearly three times the optimal level.
High insulin (hyperinsulinemia) means your body is producing massive amounts of insulin to keep glucose in range — a sign of significant insulin resistance. And high insulin is one of the most powerful drivers of fat storage the human body has. Specifically, it locks fat in fat cells and makes burning stored fat nearly impossible regardless of caloric deficit.
This is why people with undetected insulin resistance can eat 1,200 calories a day and still not lose weight. The hormonal environment simply won’t allow fat to be released. Fasting insulin is almost never included in a standard metabolic panel — you must request it specifically.
4. Ferritin of 9 ng/mL (Iron Deficiency Without Anaemia)
Standard iron panels check haemoglobin and haematocrit — and both of mine were normal, so previous doctors concluded I wasn’t anaemic and moved on. But ferritin (the protein that stores iron) tells a completely different story. At 9 ng/mL, my iron stores were critically depleted.
Ferritin below 30 ng/mL is associated with chronic fatigue, anxiety, hair loss, shortness of breath during exercise, and difficulty concentrating — all symptoms I had attributed to stress and “just how I am.” Many functional medicine practitioners consider optimal ferritin for women to be 70–100 ng/mL. Most conventional doctors don’t check ferritin without an overt anaemia diagnosis.
What Changed After Treatment
Within 6 months of addressing all four deficiencies — therapeutic vitamin D supplementation, low-dose thyroid hormone (Armour Thyroid), a low-carbohydrate diet targeting insulin resistance, and iron supplementation — the results were extraordinary:
- 28 pounds lost — without counting calories or extreme restriction
- Anxiety reduced by approximately 70% — without psychiatric medication
- Energy restored — waking up rested for the first time in years
- Brain fog cleared — I could think clearly, remember things, focus on work
- Hair stopped falling out — this one I hadn’t even connected to the deficiencies
I’m not sharing this to suggest my experience will be exactly yours. Bodies are different, underlying causes vary, and medical treatment must be personalised. I’m sharing it because I spent four years suffering from problems that had a clear, testable, treatable root cause — and not a single doctor ordered the right tests until year five.
The Tests to Ask Your Doctor to Run (Print This List)
If you have unexplained weight gain, fatigue, anxiety, or depression — especially if standard workups have come back “normal” — ask your doctor to order the following. Many are covered by insurance:
| Test | What It Catches | Why Standard Panels Miss It |
|---|---|---|
| 25-Hydroxy Vitamin D (25(OH)D) | Vitamin D deficiency | Not included in standard metabolic panels |
| Full Thyroid Panel (TSH, Free T3, Free T4, TPO Ab, TGAb) | Hypothyroidism, Hashimoto’s | Standard panels only check TSH |
| Fasting Insulin | Insulin resistance (even with normal glucose) | Almost never included in standard labs |
| Ferritin | Iron storage depletion | Only ordered if haemoglobin shows anaemia |
| hs-CRP (high-sensitivity CRP) | Systemic inflammation | Not standard; must be requested |
| Homocysteine | B12/folate deficiency, cardiovascular risk | Not standard; must be requested |
| Cortisol (morning serum or 4-point saliva) | Adrenal dysfunction, chronic stress response | Not standard; saliva test often requires functional medicine doctor |
| Sex Hormones (Oestradiol, Testosterone, DHEA, SHBG) | Hormonal imbalances affecting weight/mood | Not standard unless reproductive issue is flagged |
Natural Support While You Wait for Results
While you’re pursuing testing and diagnosis, these evidence-backed interventions support all four systems simultaneously and are low-risk for most healthy adults:
For Vitamin D Deficiency
Most adults are deficient and need 2,000–5,000 IU of Vitamin D3 daily with K2 (to direct calcium properly). Get your level tested first — therapeutic repletion for severe deficiency requires higher doses under medical supervision.
For Thyroid Support
Selenium (200mcg/day) is essential for thyroid hormone conversion and has been shown in clinical trials to reduce thyroid antibodies in Hashimoto’s. Zinc, iodine (from food sources like seaweed), and avoiding environmental toxins (BPA, fluoride in large amounts) also support thyroid function.
For Insulin Resistance
The most powerful non-pharmaceutical intervention for insulin resistance is a low-carbohydrate or ketogenic diet combined with resistance training. Berberine (500mg 2x/day with meals) has strong clinical evidence for reducing fasting insulin. Magnesium glycinate (400mg before bed) also improves insulin sensitivity and sleep quality simultaneously.
For Iron/Ferritin
Iron supplementation should always be guided by your test results and doctor — excess iron is harmful. If confirmed deficient, iron bisglycinate is better tolerated than ferrous sulfate with fewer GI side effects. Taking iron with vitamin C dramatically increases absorption.
Finding a Doctor Who Will Run These Tests
Unfortunately, the standard-of-care in conventional medicine often doesn’t include comprehensive functional testing. If your current doctor won’t order these panels, here are your options:
- Functional medicine doctors specialise in root-cause medicine and comprehensive lab work. The Institute for Functional Medicine (IFM) directory at ifm.org lists certified practitioners.
- Direct-to-consumer lab testing: Services like Ulta Lab Tests, Walk-In Lab, and LabCorp Patient allow you to order your own comprehensive blood panels without a doctor’s order in most states. A full functional panel costs $150–$400 out of pocket.
- Integrative endocrinologists often bridge conventional and functional approaches, particularly for thyroid and metabolic issues.
- Ask your insurance: Many of these tests are covered when ordered with appropriate diagnostic codes for fatigue, unexplained weight gain, or mood disorders. Your doctor may simply not know to order them — showing them this list and asking directly often works.
The Bottom Line
If you’ve been told your labs are “normal” but you still feel exhausted, anxious, and can’t lose weight no matter what you try — normal doesn’t mean optimal, and comprehensive doesn’t mean standard.
The four conditions I described — vitamin D deficiency, subclinical hypothyroidism, insulin resistance with normal glucose, and iron deficiency without anaemia — are extraordinarily common, underdiagnosed, and fully treatable. They are also among the most common underlying drivers of the obesity, anxiety, and fatigue epidemic affecting millions of adults.
You deserve answers. Not to be told to try harder. Get the tests. Find a doctor who will look deeper. Your body isn’t broken — it may just be missing information.