This sensitivity arises from the indole ring of Trp, which is characterized by a relatively large dipole moment both in the ground and excited states it extensively interacts with polar and charged groups in its environment, and whose photophysical properties are affected by surrounding residues, solvent exposure, and molecular motion (Lakowicz, 1983
In addition, vitamin B12 is necessary for myelin sheath and nerve conduction, for neurotransmitters and brain metabolism, and for maintaining mood
Instead of applying it to the scalp, it's taken as a small daily tablet under a doctor's supervision
Individual testing is expensive, but researchers can share costs by organizing group testing of common products
Older adults: Potentially up to 43% of older adults may be deficient in B12, depending on the definition used - that's due to not having enough IF to aid absorption
CL Answer Can supplements, natural eye drops, or lifestyle modifications improve symptoms of dry eye