Note: This is not medical advice
Studies treating mild to moderate B12 deficiency in older people have failed to provide cognitive benefits: A clinical trial from the Netherlands measured the cognitive response to B12 supplements in people 70 years old with mild B12 deficiency and MMA levels 320 nmol/l (average: ~450 nmol/l)

Here are the main signs and symptoms of B12 deficiencies that show up at this stage of life: Tiredness and fatigue Difficulty thinking or memory issues Low moods such as apathy, depression, or irritability Digestive complaints Issues staying asleep Feeling like your heart is racing and pounding Other common complaints include Numbness, tingling, or other altered nerve like sensations in your body such as burning feet Clumsiness, balance, or gait problems Development of tremors Vision changes Feeling light-headed, weak, or dizzy Feeling short of breath Having an inflamed red tongue Loss of appetite Cardiovascular complications Bone loss You can assess your B12 levels in a few different ways You can test B12 on its own and depending on where you live in the world this range varies significantly, which is insane
Baum N, Eggers M, Koenigsdorf J, Menzel S, Hambach J, Staehler T, et al
Inositol, a nutrient belonging to the B vitamin complex, is closely associated with Choline
Moreover, it helps enhance mental and cognitive function, help you lose weight, and reduce your risk of heart disease and other significant health issues