Nutrition at 38: Thyroid, Ferritin and the Tired Years
Persistent tiredness at 38 is usually attributed to work and children, and in a large share of cases it is actually one of four correctable things. Thyroid dysfunction, low ferritin, vitamin D deficiency and low B12 between them explain a great deal of unexplained fatigue in Indian adults, and all four are inexpensive to test and straightforward to treat.
- Hypothyroidism is common in India and disproportionately affects women in their thirties and forties.
- Ferritin can be low — causing fatigue and hair loss — while haemoglobin is still normal.
- Vitamin D insufficiency is the norm rather than the exception among Indian urban adults.
- B12 deficiency is common in lifelong vegetarians and causes fatigue, tingling and low mood.
- 'Tired because of work' is a diagnosis of exclusion, and at 38 it should be made after the tests, not before.
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The four tests
| Test | what it detects | typical cost in India |
|---|---|---|
| TSH | Thyroid underactivity | ₹150–400 |
| Ferritin | Iron stores, before anaemia appears | ₹400–800 |
| 25-OH vitamin D | Vitamin D status | ₹800–1,500 |
| Vitamin B12 | B12 status | ₹500–1,000 |
Together these cost less than a month of most gym memberships, and between them they account for a very large share of the fatigue that people at this age attribute to their schedule.
The reason to do them at 38 specifically is that this is the decade in which all four become more likely at once: thyroid disease rises with age and after pregnancies, iron stores deplete over years of menstruation, vitamin D falls with indoor working life, and B12 deficiency in vegetarians is cumulative over decades rather than sudden.
Ferritin, and why a normal haemoglobin is not reassuring
This is the most commonly missed of the four. Haemoglobin is the last thing to fall when iron runs out, not the first. The body depletes stored iron — which ferritin measures — well before red blood cell production is affected.
So a woman can be told her haemoglobin is normal, and be genuinely iron deficient, with fatigue, hair shedding, poor exercise tolerance and difficulty concentrating. The phrase to know is 'iron deficiency without anaemia', and it is common.
Reference ranges for ferritin are wide and the lower bound is often set low. Many clinicians consider symptoms plausible below about 30 ng/mL even though laboratory ranges may begin lower. If you are tired and shedding hair with a ferritin of 12, 'within range' is not the same as 'fine'.
Heavy menstrual bleeding is the usual cause in this age group, and it is both common and frequently normalised to the point of not being mentioned to a doctor.
Thyroid, which is genuinely common in India
Hypothyroidism affects a substantial share of Indian adults, with a marked female predominance, and prevalence is higher in inland regions than coastal ones — a pattern linked to historical iodine availability.
The symptoms are unhelpfully generic: fatigue, weight gain, cold intolerance, dry skin, hair loss, low mood, constipation. Every one of those is attributable to being 38 with a job and children, which is why the condition is frequently missed for years.
It is diagnosed by a blood test and treated with a daily tablet. Subclinical hypothyroidism — raised TSH with normal thyroid hormone — is a greyer area where treatment decisions depend on symptoms, antibodies and whether pregnancy is planned, and is a conversation with a doctor rather than something to resolve from an article.
One dietary note worth correcting: cruciferous vegetables such as cabbage and cauliflower are often blamed for thyroid problems. At normal culinary intakes in people with adequate iodine, the effect is not meaningful. Iodised salt matters considerably more.
What nutrition can and cannot fix
An honest division is useful here, because a great deal of fatigue content online implies that food solves all of it.
| Problem | does nutrition fix it |
|---|---|
| Low ferritin | Partly — diet helps, but depleted stores usually need supplementation |
| Low vitamin D | Rarely by diet alone — supplementation is usually required |
| Low B12 | No, if deficient — supplementation needed, especially for vegetarians |
| Hypothyroidism | No — this is a medication question |
| Low protein, high refined carbohydrate | Yes — this is genuinely dietary |
| Poor sleep | Partly — caffeine timing and late eating both matter |
The last two rows are where food actually earns its place. A day built on tea, biscuits, white rice and a token dal produces post-meal energy crashes and insufficient protein, and that produces real tiredness independent of any deficiency.
Protein at breakfast, fibre at every meal, and caffeine stopped by early afternoon address the dietary share of the problem. They will not fix a TSH of 8.
A reasonable plan at 38
- Get the four tests — before concluding anything about your schedule.
- Treat what is found, properly — iron repletion in particular takes months, not weeks, and stopping when you feel better leaves stores empty.
- Separate tea and coffee from meals by an hour — tannins impair non-haem iron absorption, and Indian meal patterns make this a frequent contributor.
- Protein at breakfast — the single dietary change most likely to alter how the day feels.
- Resistance training twice a week — counterintuitive when exhausted, reliably effective for energy over weeks.
Nutrition at 40 continues with the change in protein guidance, and nutrition at 45 covers perimenopause, which for many Indian women begins earlier than expected and overlaps heavily with the symptoms described here.
Where KABO fits in
If a blood test shows low ferritin, B12, vitamin D or a raised TSH, those are medical problems with medical answers. No shake corrects a thyroid level, and treating fatigue as a nutrition problem before testing is how years get lost.
The dietary share of the problem is real though, and it is mostly breakfast: tea and biscuits produce a crash by eleven. A KABO serving provides 25 g of complete plant protein with 26 vitamins and minerals, which is a different start to the day. Test first; fix the diet alongside whatever the tests find.
Butter Coffee — All-in-One Nutrition Shake
25 g complete plant protein, 60+ superfoods, 26 vitamins & minerals, probiotics & digestive enzymes — in one 90-second shake.
Read next
- Nutrition at 37: Your Gums Affect More Than Your Teeth
- Nutrition at 39: The Audit to Do Before You Turn 40
- Nutrition at 36: Salt, and the Silent Number
- Nutrition at 35: Indian Hearts Age Ten Years Early
- Nutrition at 40: The Year Protein Targets Change
- The Ultimate Nutrition Guide for 2026: Why Most People Feel Tired, Confused About Food, and How to Actually Fix It
Frequently asked questions
Why am I always tired at 38?
Frequently one of four correctable things rather than simply work: thyroid dysfunction, low ferritin, vitamin D deficiency or low B12. All four are common in Indian adults, all four produce generic fatigue, and all four are inexpensive to test. Attributing it to your schedule is reasonable only after they have been ruled out.
Can you be iron deficient with normal haemoglobin?
Yes, and it is common. Haemoglobin falls last; stored iron, measured by ferritin, depletes well before red cell production is affected. Iron deficiency without anaemia causes fatigue, hair shedding and poor concentration, and is missed when only haemoglobin is checked.
What ferritin level causes symptoms?
Laboratory lower bounds are often set low, but many clinicians consider symptoms plausible below roughly 30 ng/mL. A result inside the reference range is not automatically adequate if you have fatigue and hair shedding, so the number is worth seeing rather than accepting 'normal'.
How common is thyroid disease in India?
Hypothyroidism affects a substantial share of Indian adults with a strong female predominance, and is more prevalent inland than on the coast, a pattern associated with historical iodine availability. Its symptoms overlap almost entirely with ordinary mid-thirties tiredness, which is why it is often missed.
Do cruciferous vegetables harm the thyroid?
At normal culinary amounts in people with adequate iodine intake, no. Cabbage, cauliflower and broccoli are frequently blamed, but the effect requires very large intakes or coexisting iodine deficiency. Using iodised salt matters considerably more than avoiding these vegetables.
Nutrition by age
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Sources
- ICMR-NIN, Nutrient Requirements for Indians (RDA 2020) and Dietary Guidelines for Indians, 2024. nin.res.in
- Unnikrishnan AG et al., "Prevalence of hypothyroidism in adults: An epidemiological study in eight cities of India", Indian Journal of Endocrinology and Metabolism, 2013;17(4):647-652.
- Ministry of Health and Family Welfare, Government of India, National Family Health Survey (NFHS-5), 2019-21.