Variables		Groups				T-Test
		Control Group (n=20)		Vit D3/Ca Group(n=20)		t	P-value
Age (years)		57.200 ± 4.916		58.500 ± 4.752		- 0.850	0.400
Weight (Kg)		85.850 ± 8.887		89.850 ± 10.989		-1.266	0.213
Height (cm)		160.600 ± 5.716		159.100 ± 5.428		0.851	0.400
2 BMI (Kg/m )		33.345 ± 3.724		35.534 ± 4.677		-1.637	0.110
Ejection fraction		59.050 ± 3.252		58.100 ± 2.882		0.978	0.334
Duration of disease (weeks)		36.400 ± 3.530		37.150 ± 3.297		-0.694	0.492
Letrozole duration (Months)		6.444 ± 1.304		6.080 ± 1.259		0.897	0.375
Variables		Group				Chi-Square
		Control Group (n=20)		Vit D3/Ca Group(n=20)
		N	%	N	%	2 X	P-value
Stage of the disease	Stage II	13	65%	10	50%	0.921	0.337
	Stage III	7	35%	10	50%
Estrogen receptor	Positive	20	100%	20	100%	-	-
	Negative	0	0%	0	0%
Progestin receptors	Positive	20	100%	19	95%	1.026	0.311
	Negative	0	0%	1	5%
HER2 receptors	Positive	4	20%	5	25%	0.143	0.705
	Negative	16	80%	15	75%
HER2-positive 1HER2-positive 2FISH or ISH		31-ve		32-ve
Types of surgery	MRM	18	90%	19	95%	0.360	0.548
	BCS	2	10%	1	5%
Chemotherapy	FAC	10	50%	8	40%	0.404	0.525
	FEC	10	50%	12	60%

Table 1: Anthropometric and clinical data measurements of the studied patients
Data are presented as mean ± SD, number and percentage Control group: postmenopausal, hormone receptor positive female patients with breast cancer received Letrozole only for 24 weeks, Vit D3/- Ca group: postmenopausal, hormone receptor positive female patients with breast cancer received Letrozole in addition to 2000IU vitamin D3 and 1000mg Calcium for 24 weeks. Kg: kilogram; cm: centimeter, BMI: body mass index, HER2: Human epidermal growth factor receptor 2, MRM: Modified radical mastecto- my, BCS; Breast conserved surgery, FAC; Fluorouracil Adriamycin cyclophosphamide, FEC: Fluorouracil Epirubicin cyclophosphamide. P-Value: comparing control group with vit D3/Ca group at baseline (Unpaired Student t-test)

Variables	Control Group(n=20)					Vit D3/Ca Group(n=20)
Variables	Baseline	After 12 weeks	P 1	After 24 Weeks	P 2	Baseline	After 12 weeks	P 3	After 24 Weeks	P 4
Vitamin D3 (ng/ml)	27.28± 8.08	25.78 ± 7.76*	<0.001	22.97 ±7.30*	<0.001	26.38±9.24	29.66±8.76*	<0.001	33.12±7.53*	<0.001
Ionized calcium (mg/dl)	4.87 ± 0.5	4.48 ± 0.58*	<0.001	4.17±0.50*	<0.001	4.70±0.51	4.84±0.50*	<0.001	5.29±0.19*	<0.001
Total Calcium (mg/dl)	9.39 ± 0.61	8.85 ± 0.72*	<0.001	7.59±0.91*	<0.001	9.28±0.67	9.55±0.47*	0.008	9.90±0.24*	<0.001
Phosphorous (mg/dl)	4.58 ± 0.51	4.05 ± 0.56*	<0.001	3.78±0.54*	<0.001	4.55±0.47	4.7±0.51*	<0.001	4.84±0.50*	<0.001
ALP (U/L)	78.10± 22.14	82.55± 23.75*	<0.001	86.95±24.9*	<0.001	85.90±24.13	82.90±23.46*	0.001	80.30±24.33*	<0.001
Osteocalcin (ng/ml)	29.13± 15.08	31.57± 15.81*	<0.001	34.22± 16.01*	<0.001	25.03±17.96	23.44±16.87*	<0.001	22.43±16.61*	<0.001
I-PTH (pg/ml)	39.9± 21.13	45.45± 20.00*	<0.001	50.70±20.51*	<0.001	39.50±9.19	37.05±8.93*	<0.001	33.20±8.66*	<0.001
HAQ II score	45.45± 1.23	38.10± 2.12*	<0.001	24.05±0.83*	<0.001	45.87±0.94	34.49±2.83*	<0.001	18.82±2.97*	<0.001
Pain Score	0.7 ± 0.58	4.3 ± 0.85*	<0.001	7.3± 0.59*	<0.001	0.5±0.76	4.0±0.76*	<0.001	6.7±0.64*	<0.001

Table 3: Biological and clinical parameters of the two study groups at baseline, 3 and 6 months after intervention
Data are presented as mean ± SD Control group: postmenopausal, hormone receptor positive female patients with breast cancer received Letrozole only for 24 weeks, Vit D3/- Ca group: postmenopausal, hormone receptor positive female patients with breast cancer received Letrozole in addition to 2000IU vitamin D3 and 1000mg Calcium for 24 weeks. ng/ml; nanogram per milliliter, mg/dl: milligram per deciliter, U/L: unit per liter, I-PTH: Intact parathyroid hormone, pg/ml: pico- gram/milliliter, BMD: bone mineral density, HAQ: health assessment questionnaire. P1-Value: comparing control group at baseline and 3 months after intervention (paired student t-test) P2-Value: comparing control group at baseline and 6 months after intervention (paired student t-test) P3-Value: comparing Vit D3/Ca group at baseline and 3 months after intervention (paired student t-test) P4-Value: comparing Vit D3/Ca group at baseline and 6 months after intervention (paired student t-test)

Variables	After 12 weeks				After 24 Weeks
	Control Group(n=20)	Vit D3/Ca Group(n=20)	T-Test		Control Group(n=20)	Vit D3/Ca Group(n=20)	T-Test
	Control Group(n=20)	Vit D3/Ca Group(n=20)	t	P 5	Control Group(n=20)	Vit D3/Ca Group(n=20)	t	P 6
Vitamin D3 (ng/ml)	25.78±7.76	29.66±8.76	-1.479	0.147	22.97±7.30	33.12±7.53*	-4.325	<0.001
Ionized calcium (mg/dl)	4.48±0.58	4.84±0.50*	-2.090	0.043	4.17±0.50	5.29±0.19*	-9.222	<0.001
Total Ca (mg/dl)	8.85±0.72	9.55±0.47*	-3.591	0.001	7.59±0.91	9.90±0.24*	-10.914	<0.001
Phosphorous (mg/dl)	4.05±0.56	4.70±0.51*	-3.829	<0.001	3.78±0.54	4.84±0.50*	-6.434	<0.001
ALP (U/L)	82.55±23.75	82.90±23.46	-0.047	0.963	86.95±24.90	80.30±24.33	0.854	0.398
Osteocalcin (ng/ml)	31.57±15.81	23.44±16.87	-1.571	0.124	34.22±6.01	22.43±16.61*	-2.286	0.28
Intact-PTH (pg/ml)	45.45±20.00	37.05±8.93	1.714	0.095	50.70±20.51	33.20±8.66*	3.515	0.001
HAQ II score	38.10±2.12	34.49±2.83*	-4.548	<0.001	24.05±0.83	18.82±2.97*	-7.573	<0.001
Pain Score	4.3±0.85	4.0±0.76	---	0.558	7.3±0.59	6.7±0.64*	---	0.005

Table 4: Comparing biological and clinical parameters of the of the two study groups 3 and 6 months after intervention
Data are presented as mean ± SD
Control group: postmenopausal, hormone receptor positive female patients with breast cancer received Letrozole only for 24 weeks, Vit D3/- Ca group: postmenopausal, hormone receptor positive female patients with breast cancer received Letrozole in addition to 2000IU vitamin D3 and 1000mg Calcium for 24 weeks. ng/ml; nanogram per milliliter, mg/dl: milligram per deciliter, U/L: unit per liter, I-PTH: Intact parathyroid hormone, pg/ml: pico- gram/milliliter, BMD: bone mineral density, HAQ: health assessment questionnaire. P5-Value: comparing control group versus vitamin D3/calcium supplementation group 3 months after intervention (Unpaired student t-test) P6-Value: comparing control group versus vitamin D3/calcium supplementation group 6 months after intervention (Unpaired student t-test)

Variables	Control group(n=20)	Vit D3/Ca Group(n=20)	T-Test
Variables	Control group(n=20)	Vit D3/Ca Group(n=20)	t	P-value
Vitamin D3 (ng/ml)	27.280 ± 8.080	26.380 ± 9.245	0.328	0.745
Ionized Ca (mg/dl)	4.870 ± 0.500	4.700 ± 0.510	1.064	0.294
Total Ca (mg/dl)	9.395 ± 0.613	9.281 ± 0.679	0.560	0.579
Phosphorous (mg/dl)	4.580 ± 0.514	4.550 ± 0.476	0.192	0.849
ALP (U/L)	78.100 ± 22.143	85.900 ± 24.138	-1.065	0.294
Osteocalcin (ng/ml)	29.130 ± 15.082	25.035 ± 17.964	-0.781	0.440
I-PTH (pg/ml)	39.900 ± 21.138	39.500 ± 9.191	0.078	0.939
BMD (t-score)	-1.935 ± 0.517	-1.830 ± 0.487	-0.661	0.513
HAQ II score	45.450 ± 1.232	45.875 ± 0.943	1.225	0.228
Pain Score	0.7 ± 0.58	0.5 ± 0.76	---	0.435

Pearson Correlations between BMD and biological markers
Vit D3/Calcium supplementation group	t-score after 24 weeks
Vit D3/Calcium supplementation group	r	P-value
Vitamin D	* 0.036	0.001
Ionized calcium	* 0.607	0. 001>
Phosphorous	* 0.599	0. 001>
Alkaline phosphatase (ALP)	* -0.565	0. 001>
Osteocalcin	* 0.150 -	0.027
Intact- parathyroid hormone (I-PTH)	* -0.405	0. 001>

Tables at a glance

Figures at a glance