What could be causing the following test results (May 7th, June 23rd, July 10th, and October 12th) ... 49 year old white female ...
Creatinine -- high normal -- 0.93, 0.99, 1.00, 0.97
eGFR -- low -- 73, 68, 59, 69
Protein -- normal to low -- 7.4, 6.5, unknown, 5.9
Iron -- low -- unknown, 30, unknown, 39
MCH -- low -- 25.9, 25.4, unknown, 26.3
MCHC -- low normal to low -- 31.5, 30.7, unknown, 31.3
RDW -- high normal to high -- 15.0, 16.1, unknown, 15.6
Hemoglobin -- low normal to normal -- 13.0, 11.9, unknown, 11.5
Cholesterol -- high normal to high (note that I used to have low cholesterol) -- 218, 224, unknown, 199
Fasting Glucose -- high normal (considering my low sugar diet) -- 94, 90, 96, 95
Vitamin D -- low normal to low (note that I have been taking dr prescribed Vitamin D Supplements for 3 months to get my levels up into normal range) -- 13.6, 20.5, 22, 34.3
Calcium -- normal to high (only once) -- 10.4, 9.5, 9.6, 9.2
PTH -- high -- unknown, 81, 115, 75