Vitamin D (25-OH)
What This Test Measures
Storage form of vitamin D; immune, bone, mood, inflammation
Conventional vs. Functional Optimal Range
The gap between these ranges is why you feel terrible with "normal" labs. Conventional medicine waits for disease. Functional medicine optimizes for health.
Gabriel's Take
Vitamin D of 35 is "normal" but below Gabriel's optimal band of 50-75 ng/mL for immune function, mood and bone health. Doses vary by person, so test, supplement, then retest. The adult upper limit is 4,000 IU a day (MedlinePlus), so take more only with a clinician checking your levels, and don't push above 75. Conventional "sufficient" (>30) is just enough to prevent rickets, not optimize health.
When This Test Is High
Toxicity (rare, >100), hypercalcemia
When This Test Is Low
Deficiency: immune dysfunction, osteoporosis, depression, autoimmunity
Related Conditions
Osteoporosis, autoimmune disease, depression, infections
Recommended Follow-Up
If low, raise it with sensible sun and vitamin D3 to reach 50-75 ng/mL; more than 4,000 IU a day only with a clinician checking blood levels; recheck in 2-3 months