Hello, thanks for the query to H.C.M.
When you take "FLINSTONES VITAMINS with IRON" than you feel difficulty to walk downstairs.
Query is that there is joint pain which creeps you?
Flintstones vitamins have nothing to do with joint pain.
Iron which is with flintstones is the main culprit which produces joint pain in your's case.
Iron toxicity detection is usually based on suspicion due to joint pain, that's in your case i.e. if you will take iron than you will have joint pain due to iron toxicity.
Elevated serum ferritin above 1000 nv/ml is an indication of iron toxicity.
When you take iron orally please note down that iron absorption is enhanced by
lysine, Vitamin "C", "E", citric acid,
glucose,fructose,
sorbitol lactate.
Protein calcium etc decrease the absorption of iron.
If you want to take vitamin than please take them , but you have to avoid "IRON" which is toxic for you.
I have seen many cases when we give IRON in injection they ( patients) develops fever
chills, rigor and
severe joint pain with red swollen joints.
Regards.
Dr. HET