There can be multiple causes of your symptoms for which proper evaluation by a Rheumatologist is necessary

Need to get blood tests done for inflammatory joint pain . Better to get a clinical examination done.

Your joint stiffness is secondary to overworked weak muscles of your body. I presume you have a desk job and the lockdown has made our body do domestic activities which it is not trained for. Thus the untrained muscles feel overworked and get stiff. So the more time you are 'inactive' more you feel stiff, especially after a long night sleep.

Consult a Rheumatologist for joint pain and stiffness.

Hello dear Thanks for reaching out. I have gone through your complaints carefully. Summarising your case you are a young active female with several months joint pain and stiffness with low vitamin D , which has not improved with vit D supplements. Now since the vit D supplementation has not worked i would need for information to have a better understanding: 1. Which joints are painful and have you noticed any swelling of joints too. 2. Have you had any fever before the onset of joint pains? 3. Is the stiffness more in the morning and if yes how long does it last> 4. Do you have associated back pain? 5. Do you have any medical problems like hypothyroid or diabetes? 6. When do the joints hurt most, say after exertion or after getting up in the morning? 7. Do you have additional symptoms like hair fall, acidity, cramps, weak memory, fatigue, tingling in hands and feet? 8. Have you taken any medicine apart from vit D? 9. If you have had any blood tests recently, i would want to have a look. Regards Dr Vipin Gupta