Nutritional Status
Optimal nutrition supports every aspect of human physiology, including energy production, immune function, neurological health, hormone regulation, tissue repair, and metabolic flexibility. Laboratory testing can help identify nutritional deficiencies or imbalances, but no single marker provides a complete assessment of nutritional status.
Many nutrient levels are influenced by recent dietary intake, inflammation, medications, gastrointestinal absorption, liver function, and overall metabolic health.
Important
Normal laboratory values do not always guarantee optimal nutritional status. Laboratory results should always be interpreted alongside symptoms, dietary habits, medical history, and other relevant biomarkers.
Vitamin D (25-Hydroxyvitamin D)
What it reflects
25-hydroxyvitamin D is the principal circulating form of vitamin D and the standard laboratory marker used to assess vitamin D status.
Why it matters
Vitamin D plays an essential role in bone health, immune regulation, muscle function, nervous system health, and numerous metabolic processes.
Reference values
Typical laboratory reference range
Generally 50–125 nmol/L (20–50 ng/mL).
Generally favourable for metabolic health
Often 75–125 nmol/L (30–50 ng/mL), interpreted alongside individual clinical circumstances.
Integra perspective
Vitamin D status reflects more than dietary intake alone. Sensible sunlight exposure, circadian health, skin pigmentation, geography, seasonal variation, and overall lifestyle all contribute significantly to vitamin D physiology.
Interpret together with
• Calcium
• ALP
• Clinical symptoms
Vitamin B12
What it reflects
Vitamin B12 is essential for neurological function, red blood cell production, DNA synthesis, and methylation.
Why it matters
Deficiency may contribute to fatigue, anaemia, neurological symptoms, impaired cognition, and elevated homocysteine.
Reference values
Typical laboratory reference range
Generally 150–700 pmol/L (approximately 200–950 pg/mL).
Generally favourable for metabolic health
Values comfortably within the upper half of the laboratory reference range are often considered reassuring when supported by normal homocysteine and clinical assessment.
Integra perspective
A laboratory result within the reference range does not always exclude functional B12 insufficiency. Homocysteine, folate, clinical symptoms, and, where available, methylmalonic acid (MMA) may provide additional insight.
Interpret together with
• Homocysteine
• Folate
• MCV
Folate (Vitamin B9)
What it reflects
Folate supports DNA synthesis, cell division, red blood cell production, and methylation.
Why it matters
Low folate may contribute to anaemia, elevated homocysteine, impaired cellular repair, and neurological dysfunction.
Reference values
Typical laboratory reference range
Reference intervals vary between laboratories.
Integra perspective
Folate should rarely be interpreted independently. Combined assessment with vitamin B12 and homocysteine provides a more meaningful evaluation of methylation and nutritional status.
Interpret together with
• Vitamin B12
• Homocysteine
• MCV
Iron Studies
What they reflect
Iron studies evaluate iron availability, transport, storage, and utilisation throughout the body.
Why they matter
Iron is essential for oxygen transport, energy production, cognitive function, and cellular metabolism.
Common laboratory markers
• Ferritin
• Serum iron
• Transferrin
• Transferrin saturation (TSAT)
• Total Iron Binding Capacity (TIBC)
Integra perspective
Iron status should never be assessed using ferritin alone. Inflammation, infection, liver disease, and metabolic dysfunction may elevate ferritin despite reduced functional iron availability. A complete iron profile provides considerably greater clinical value.
Interpret together with
• Complete Blood Count (CBC)
• Ferritin
• hs-CRP
Magnesium
What it reflects
Magnesium is an essential mineral involved in more than 300 enzymatic reactions, including energy production, muscle function, nervous system regulation, glucose metabolism, and electrolyte balance.
Why it matters
Magnesium requirements often increase during periods of physiological stress and nutritional ketosis due to increased renal excretion.
Reference values
Typical laboratory reference range
Generally 0.70–1.05 mmol/L.
Important limitation
Only a very small proportion of total body magnesium circulates in the blood. Serum magnesium may therefore remain normal despite significant intracellular deficiency.
Integra perspective
Normal serum magnesium does not necessarily indicate adequate body magnesium stores. Clinical symptoms, dietary intake, and overall metabolic context remain important considerations.
Interpret together with
• Potassium
• Calcium
• Clinical symptoms
Zinc
What it reflects
Zinc is an essential trace mineral involved in immune function, wound healing, enzyme activity, antioxidant defence, hormone regulation, and cellular repair.
Why it matters
Zinc deficiency may impair immune function, wound healing, taste perception, skin health, and reproductive physiology.
Reference values
Typical laboratory reference range
Reference intervals vary between laboratories.
Integra perspective
Serum zinc provides only a partial assessment of zinc status and may be influenced by inflammation, infection, recent dietary intake, and stress. Interpretation should always consider dietary history and clinical presentation.
Interpret together with
• Copper (when available)
• hs-CRP
• Clinical symptoms
Looking at the Whole Picture
No single nutrient marker accurately reflects overall nutritional status.
For example:
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Vitamin D depends heavily on sunlight exposure as well as dietary intake.
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Vitamin B12 should be interpreted alongside homocysteine, folate, and clinical symptoms.
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Folate and vitamin B12 work together within methylation pathways and should rarely be assessed independently.
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Iron status requires a complete iron profile rather than ferritin alone.
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Serum magnesium represents only a small fraction of total body magnesium.
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Zinc values may appear normal despite functional deficiency.
Meaningful assessment comes from combining laboratory findings with dietary habits, symptoms, metabolic health, and clinical context.
Core Principle
Optimal nutritional status is not defined solely by laboratory values but by the body's ability to effectively utilise essential nutrients to support normal physiological function.
Laboratory testing provides valuable guidance, but meaningful interpretation requires consideration of diet, lifestyle, metabolic health, inflammation, sunlight exposure, gastrointestinal function, and the individual's overall clinical presentation.