Hi, Around 2 years back I was suffering from vitamin b12 and vitamin D deficiency. I had visited a physician and he had suggested some capsules for vitamin b12 and "D-Rise" capsule for vitamin D. At that time both the vitamin levels  bounced back to normal. However, recently I just went through a random test and found that though vitamin b12 levels are normal, vitamin D level has again come below the threshold. Vitamin D values are 14 Ng/ml as of now. Shall I take the vitamin D supplements again? Also, my worry is why the vitamin D levels are not maintained consistently? Do I need to undergo any specific treatment for that? Please suggest.