Most diet conversations start and end with macros: how much protein, how many grams of carbohydrate, how much fat. That framing is useful but incomplete. A plan can hit every macro target on paper and still leave a patient fatigued, foggy, slow to recover, hair shedding, and mood quietly off — because calories tell only half the story. The other half is what those calories carry with them: the vitamins, minerals, and trace elements that quietly run the machinery of metabolism. This is the practitioner’s primer on what to actually look for, what to test, and how to design adequacy into a plan rather than discover its absence three months in.
What micronutrients actually do
Micronutrients are the vitamins (A, C, D, E, K, and the B-complex) and minerals (iron, calcium, magnesium, zinc, selenium, iodine, copper, chromium, manganese, and several others) the body needs in small but non-negotiable amounts. They do not provide energy themselves. They are the cofactors and catalysts that let the body extract energy from food, build tissue, fire neurons, regulate hormones, and defend against oxidative stress.
The cofactor logic
Take a single example. Converting carbohydrate into usable cellular energy requires thiamine (B1), riboflavin (B2), and niacin (B3) at multiple enzymatic steps. Run low on any of them and the system slows — not catastrophically, but enough to register as the vague tiredness patients struggle to describe to their GP. The pattern repeats across every metabolic pathway. Thyroid hormone synthesis needs iodine, selenium, and tyrosine. Methylation needs folate, B12, B6, and magnesium. Collagen synthesis needs vitamin C, copper, and zinc. Insulin sensitivity is modulated by chromium and magnesium. Adequacy is the invisible scaffolding under everything macros are trying to achieve.
Why macro-perfect plans can fail
It is entirely possible to build a 1,800-calorie plan that meets protein targets and creates a tidy deficit while still being micronutrient-poor. Diets dominated by refined grains, packaged snacks, and a narrow rotation of “safe” foods hit calorie goals because the food is calorie-dense — but they deliver only a fraction of the vitamin and mineral load a varied plant-and-protein pattern would provide. The patient experiences the result before any test does: declining workout recovery, hair shedding, slower wound healing, irregular cycles, frequent low-grade infections, mood dips. These are not signs of “needing more discipline.” They are signs the diet is mathematically correct and biologically incomplete.
The deficiencies hiding in Indian clinical practice
Population-level surveys in India consistently flag a handful of deficiencies even among well-fed urban adults. Knowing them on sight saves an enormous amount of trial-and-error.
Vitamin D
India’s vitamin D deficiency prevalence sits between 70–90% across most studied populations — paradoxical for a country with abundant sunlight, but explained by indoor work, conservative dress, sunscreen use, and pigmentation. Clinical consequences extend far beyond bone health: insulin resistance, immune dysfunction, mood disturbance, and chronic inflammation all correlate. Target 25(OH)D level: 40–60 ng/mL. Most patients need 2,000–4,000 IU/day to maintain, with higher loading doses for confirmed deficiency. Pair with K2 (MK-7) and adequate magnesium for proper utilisation.
Vitamin B12
Common in long-term vegetarians and vegans, but absorption issues affect omnivores too — particularly older adults, patients on long-term PPI therapy, and those with metformin use or H. pylori history. The lab picture is more nuanced than total B12: serum B12 misses functional deficiency in 20–30% of cases. Order methylmalonic acid (MMA) and homocysteine alongside serum B12 for a complete picture. Target serum B12: >500 pg/mL; MMA <0.4 nmol/L. Methylcobalamin or adenosylcobalamin forms outperform cyanocobalamin in MTHFR variant carriers (see our nutrigenomics primer).
Iron
Still the most common deficiency in women of reproductive age in India and a frequent driver of “unexplained” fatigue. The mistake is testing only haemoglobin — by the time Hb drops, iron stores have been depleted for months. Order ferritin first. Target ferritin: 50–150 ng/mL for most adults; below 30 ng/mL is depletion regardless of Hb. Pair with transferrin saturation to distinguish iron deficiency from inflammation-driven low iron. Heme iron sources (where dietary pattern permits) outperform non-heme; vitamin C at the same meal triples non-heme absorption; tea and coffee at the meal cut it in half.
Magnesium
The most underdiagnosed deficiency in clinical practice, in part because serum magnesium is a poor marker (the body maintains serum levels by pulling from bone and tissue). Estimated 60–80% of Indian adults consume below RDA. Symptoms — muscle cramps, restless sleep, anxiety, constipation, blood pressure dysregulation — are common and routinely missed. RBC magnesium is more reliable than serum. Dietary sources cluster in dark leafy greens, pumpkin seeds, almonds, dark chocolate, and beans. Supplementation: glycinate or threonate forms over oxide; 300–400 mg/day for adults.
Iodine and selenium (the thyroid pair)
Iodine deficiency has dropped in India since salt iodisation, but pockets remain — particularly in regions consuming non-iodised rock salt or in patients with high goitrogen intake. Selenium deficiency is less talked about but increasingly relevant — most Indian soils are selenium-poor, and the resulting tissue depletion impairs thyroid hormone conversion (T4 → T3). The thyroid panel is incomplete without these two minerals in the picture, particularly in subclinical hypothyroid patients who fail to respond to standard treatment.
When genes change the math
The same intake does not become the same nutrient in every body. Variants in MTHFR reduce conversion of folate to its active form (5-MTHF), raising requirement for active folate over synthetic folic acid. Variants in VDR affect vitamin D receptor binding and downstream response. PEMT variants raise dietary choline requirements. Iron-handling polymorphisms (HFE) predispose to either deficiency or overload. TCF7L2 variants worsen the metabolic consequences of any nutritional deficiency that touches glucose handling.
Nutrigenomics moves from interesting to actionable here. A genetic report does not replace dietary intake or blood work — it explains why two patients on the same regimen show very different lab values. It points to the form, the dose, and the cofactors that will actually move the needle. The full nutrigenomics framework walks through which variants matter most.
The clinical workup — what to actually test
A baseline micronutrient panel for any patient presenting with the classic deficiency cluster (fatigue, hair shedding, poor recovery, mood dips, immune fragility) should usually include:
- 25(OH) vitamin D — the single highest-yield test in Indian clinical practice
- Serum B12, methylmalonic acid, homocysteine — for the full B12 picture, not just total
- Ferritin, serum iron, total iron-binding capacity, transferrin saturation — the iron panel, not just Hb
- RBC magnesium — more reliable than serum
- Zinc and copper (with copper:zinc ratio) — for immune and metabolic context
- Full thyroid panel (TSH, free T4, free T3, anti-TPO) — for the thyroid-micronutrient axis
- Folate (red cell folate preferred over serum)
- Vitamin B6 (PLP) and vitamin A if dietary history suggests indication
For women with cycle irregularity or PCOS, layer this panel onto the metabolic workup detailed in our PCOS guide — the two pictures overlap in important ways, and treating one without the other often under-performs.
Supplementation, done right
Generic multivitamins solve no problem precisely. Some nutrients are antagonistic at high doses (calcium and magnesium compete for absorption; zinc and copper compete; iron blocks zinc). Others require cofactors to function (D needs K2 and magnesium; B12 works better with the rest of the B-complex). Iron supplementation given without confirmed need can actively cause harm via oxidative stress and GI disruption.
The clinical sequence that produces results: test first, supplement targeted forms at clinically meaningful doses for confirmed deficiencies, re-test at 8–12 weeks, then taper to dietary maintenance once stores are restored. Patients who stay on supplements indefinitely without re-testing are guessing; patients who only address diet without measuring miss the depletion that is actively undermining their plan.
Micronutrient adequacy is the invisible foundation of every nutritional intervention. Macro plans that ignore it produce the patient who “did everything right” and got nowhere — because the body cannot run on a depleted toolkit no matter how cleanly the energy budget balances. The interplay between absorption and gut health matters too: a perfect supplement protocol fails in a patient with poor gut integrity, which is why we cover the gut side in our field guide to gut health. At Horta Nutrition, every personalised diet plan we build for practitioners in our network is engineered for micronutrient adequacy first — because no macro target is worth hitting on a depleted foundation. The free practitioner guide walks through how the full picture comes together in clinical practice.
