Locally harvested foods support serum 25-hydroxyvitamin D sufficiency in an indigenous population of Western Alaska

Figures & data

Table I. Age, dietary and clinical characteristics of 497 Alaska Native men and women^a

Characteristic	n	Mean	Median	Men	Women	P
Sampling period	497			213	284	<0.01^b
Synthesizing^c	247			100	147	0.29
Non-synthesizing	250			113	137
Age, years	497	39.0±17.4	38	39.4±18.0	38.7±16.9	0.68^d
BMI (kg/m^2)	497	27.7±6.12	26.8	25.9±4.48	29.1±6.79	<0.01
Vitamin D intake (µg/d)	497	15.1±20.2	8.6	18.0±25.8	12.9±14.4	<0.01
Calcium intake (mg/d)	497	416±293	340	470±340	376±244	<0.01
Energy from local foods (%)	497	22.9±17.1	18.9	23.0±17.6	22.8±16.7	0.9
Serum 25(OH)D (nmol/L)	497	95.6±40.7	89.9	101.1±44.4	91.6±37.2	0.01
Synthesizing	497	103.1±41.2	102.3	109.0±43.4	92.9±39.3	0.07
Non-synthesizing	497	88.3±38.9	82.4	93.9±44.5	83.6±33.0	0.04

BMI=body mass index.

^aData include counts, means±standard deviation and medians.

^bPearson χ², like values. P=0.29 for sampling differences by sex by season.

^cMarch 22–September 21.

^d t-test, like values.

Table II. Frequency distribution by quartile of serum 25-OHD among 497 Alaska Native men and women of demographic, dietary and clinical characteristics, and season^a

Variable	1	2	3	4	P^b
Median [IQR]	52.4 [17.5–64.9]	77.4 [67.4–89.9]	104.8 [92.4–120]	147 [122–270]
Age					<0.01
<20	57 (11.5)	28 (5.6)	8 (1.6)	3 (0.6)
20–49	60 (12.1)	85 (17.1)	63 (12.7)	45 (9.1)
≥50	7 (1.4)	17 (3.4)	56 (11.3)	68 (13.7)
Gender					0.09
Men	77 (15.5)	72 (14.5)	79 (15.9)	56 (11.3)
Women	47 (9.5)	58 (11.7)	48 (9.7)	60 (12.1)
BMI					0.43
<25	55 (11.1)	47 (9.5)	38 (7.6)	45 (9.1)
25–29.9	35 (7)	45 (9.1)	47 (9.5)	38 (7.6)
≥30	34 (6.8)	38 (7.6)	42 (8.5)	33 (6.6)
Sampling period					<0.01
Non-synthesizing^c	79 (15.9)	73 (14.7)	54 (10.9)	44 (8.9)
Synthesizing	45 (9.1)	57 (11.5)	73 (14.7)	72 (14.5)
Vitamin D intake					<0.01
Lower	96 (19.3)	66 (13.3)	59 (11.9)	29 (5.8)
Upper	28 (5.6)	64 (12.9)	68 (13.7)	87 (17.5)
Calcium intake					0.11
Lower	53 (10.7)	65 (13.1)	62 (12.5)	68 (13.7)
Upper	71 (14.3)	65 (13.1)	65 (13.1)	48 (9.7)
Percent of energy from locally harvested foods					<0.01
Lower	84 (16.9)	66 (13.3)	60 (12.1)	38 (7.6)
Upper	40 (8)	64 (12.9)	67 (13.5)	78 (15.7)

BMI=body mass index.

^a n (Total %).

^bPearson χ².

^cSeptember 22–March 21.

Table III. Multiple linear regression prediction of serum 25(OH)D among 497 Alaska Native men and women^a

	Statistic
Term	Beta	Std Beta	P
Intercept	39.7±5.02^b		<0.01
Age 20–50 (year, referent 14–19)	26.5±4.2	0.26	<0.01
Age≥50 (year, referent 20–50)	32.0±3.5	0.36	<0.01
Men (referent women)	6.5±3.1	0.08	0.03
BMI 25–30 (referent≥30)	1.8±3.7	0.02	0.63
BMI <25 (referent 25–30)	9.1±3.6	0.11	0.01
Sampling period^c (referent non-synthesizing)	17.8±2.9	0.22	<0.01
Vitamin D, upper 50th % (referent lower 50th percentile)	7.2±3.3	0.09	0.03
Calcium, upper 50th % (referent lower 50th percentile)	0.1±3.1	0.00	0.99
Local food^d, upper 50th % (referent lower 50th percentile)	10.3±3.6	0.13	<0.01

BMI=body mass index.

^anmol/L.

^bIncreased endogenous vitamin D synthesizing, March 22–September 21.

^cMean±SE.

^dLocally harvested foods.

Table IV. Leading sources of vitamin D among Alaska Natives of Western Alaska^a

	% of total
Food source
Locally harvested	89.9
Market	10.1
Major food groupings^b
Meats	92.5
Dairy	3.75
Grains	2.1
Eggs	1.1
Beverages	0.2
Minor food groupings^b
Fish	90.1
Milk	3.2
Cereals	1.2
Eggs	1.1
Beef	1
Individual foods
Whitefish	35.4
Salmon	26.8
Herring	13.1
Blackfish	4.1
Pike	3.1

^aUp to 5 sources shown.

^bIncludes mixed dishes.