Definitely vit D, B12, calcium, magnesium and ask your doctor to test your levels. I was completely depleted and didn't even know it 2 1/2 years after chemo! Turns out chemo caused the anti parietal antibody in my intestines and I can't absorb them orally so am on monthly injections for life. Chemo can alter your body and its ability to process nutrients. Pay attention to fatigue levels. I felt like chemo
Fatigued even years later which pushed me to get checked.

I'm a pharmacist - I would not advise any supplements unless your Oncologist has specifically advised. I won't go into my soapbox about supplements, but you need to remember that none of them have to be proven either safe or effective --- they aren't regulated by the same FDA processes that regulate medications.

I have been drinking a powder that is called smart mix, it is made by Zija. I felt better within 5 days of drinking this and dont think I will ever stop. You can find it on line at Zija.com. It is packed full of every vitamin, mineral or nutrient you could need. No need for me to take a million supplements a day. Its very safe, I put it in a fruit smoothie every morning, and share it with my 4 year old granddaughter. It does not taste bad. On days when I am in a hurry I just dump it in a bottle of water and drink up. There is also a tea that I drink a couple of nights a week from the same company. It detoxifies you liver. I feel much less sluggish. Its wonderful!!! My friend who is an oncology research nurse told me about it.
Thanks
Gayla

To keep healthy vit D, B6 for red blood cells, minerals tend to get depleted so a good multi vitamin/mineral can help too. I heard to avoid iron though.

yes, always preface your responses with...ask your Dr. first :-) but it's nice to share what worked for you and what didn't :p