Just like djembe heads, not all djembe tuning rope is created equal. Low quality rope on a djembe can truly make an otherwise excellent drum sound sub par. When selecting a rope-tuned djembe, make sure that the rope used is internally braided and non-stretch. This allows the tuning to stay in place.
If multivitamins make you feel exhausted, just stop taking them. But I think you were just drowsy an hour after taking it, which is an effect of some multi vitamins but my mom is taking One a day for women, it boosts her energy, she doesn't get tired that easily. Maybe you just have to try another multi vitamins,
A. Yes low level of vitamin B12 is associated with depression. You can complete its deficiency by having good diet which will cover the B12 requirements. What happens that depressed people tend to eat less of healthy food and which reduces the B12. So, it again reduces the capacity to fight against the depression.