Vitamin D

Vitamin D is a nutrient that helps the body absorb and use calcium and phosphorous, which are important in the maintenance of healthy bones. Vitamin D may also be related to other health outcomes but at this time the evidence is inconsistent.

Vitamin D is stored in body fat tissue. Vitamin D deficiency results in abnormal bone metabolism, which may lead to rickets (deformations of the skeleton) in children, and osteomalacia (undermineralized bones) or osteoporosis (porous bones) in adults. Excessive intake of vitamin D results in hypercalcemia (too much calcium in the blood) which can lead to calcification of the kidneys and other soft tissues including the heart, lungs and blood vessels.

Dietary Sources

Vitamin D is found naturally in only a few foods such as fatty fish and egg yolks. The major sources of vitamin D in the Canadian diet are fortified milks and margarines.

Vitamin D is unique because it can also be synthesized by the skin following sun exposure. However, season, time of day, cloud cover, smog, skin pigmentation and sunscreen use are all factors that can affect vitamin D synthesis in the skin.

Assessment of Vitamin D Status

Plasma 25-hydroxy-vitamin-D (25OHD) was selected as the measure of vitamin D status because levels of this indicator reflect total vitamin D exposure from foods, supplements, and synthesis in the skin.

Table: Plasma 25-hydroxyvitamin D (nmol/L),
Mean and selected percentiles of plasma concentrations, by DRI age groups and sex, Canada household population, Canadian Health Measures Survey 2007 to 2009

E Data with a coefficient of variation (CV) from 16.6% to 33.3%; use with caution

Sex
Age Group
n
Mean
(95% conf. interval)
Selected percentiles
 (95% confidence intervals)
5th
10th
25th
50th
75th
90th
95th
Males
9-13 408 73.4
(69.7,77.2)
36.5
(31.1,41.9)
43.4
(36.7,50.0)
56.7
(51.5,61.9)
72.1
(68.4,75.8)
88.9
(81.3,96.4)
105.7
(99.5,111.9)
113.4
(107.8,119.0)
14-18 284 65.2
(57.2,73.1)
27.6
(20.3,35.0)
30.8
(22.3,39.2)
43.1
(32.4,53.9)
63.0
(54.8,71.2)
83.0
(74.6,91.4)
98.6
(86.9,110.2)
110.8
(98.5,123.1)
19-30 296 62.5
(53.3,71.7)
24.3
(17.7,31.0)
32.1
(23.0,41.3)
43.2
(36.1,50.2)
58.7
(50.7,66.6)
72.9
(59.0,86.8)
90.4
(71.1,109.7)
114.0
(74.9,153.1)
31-50 656 61.6
(57.0,66.2)
25.9
(24.0,27.7)
31.2
(26.8,35.5)
45.1
(40.9,49.4)
59.5
(52.8,66.3)
76.2
(68.8,83.6)
91.8
(83.8,99.8)
100.0
(89.9,110.2)
51-70 550 69.2
(65.4,73.1)
29.5
(25.2,33.9)
36.4
(29.5,43.4)
50.1
(46.6,53.6)
67.4
(62.4,72.4)
85.3
(79.1,91.4)
101.4
(93.8,109.0)
113.8
(104.8,122.9)
71-79 173 73.7
(67.1,80.3)
40.8
(36.9,44.7)
46.8
(42.4,51.2)
58.2
(51.6,64.9)
71.2
(60.6,81.9)
88.9
(78.5,99.4)
99.2
(90.9,107.5)
105.3
(91.9,118.6)
19-79 1675 64.7
(61.0,68.3)
26.6
(23.2,30.0)
33.8
(29.6,38.0)
46.9
(43.5,50.3)
62.3
(57.9,66.8)
80.0
(75.4,84.7)
95.4
(90.0,100.7)
108.2
(98.8,117.6)
Females
9-13 385 69.5
(63.6,75.5)
35.9E
(22.0,49.8)
42.6
(34.0,51.2)
55.4
(49.0,61.8)
68.4
(63.1,73.7)
83.4
(77.4,89.3)
99.4
(89.5,109.3)
107.4
(99.6,115.3)
14-18 285 68.6
(63.0,74.2)
27.0
(18.5,35.4)
35.6
(24.6,46.5)
50.1
(42.6,57.7)
64.3
(57.4,71.1)
86.4
(74.9,97.9)
103.7
(87.9,119.5)
118.2
(99.7,136.8)
19-30 336 72.5
(67.2,77.9)
31.7
(27.3,36.0)
36.9
(32.9,41.0)
49.7
(43.9,55.5)
68.3
(61.9,74.8)
88.3
(80.2,96.3)
106.5
(89.0,123.9)
130.0
(111.5,148.5)
31-50 789 67.1
(63.7,70.4)
31.9
(26.9,37.0)
38.6
(33.7,43.6)
49.4
(44.9,53.9)
66.0
(62.0,70.1)
80.4
(76.1,84.6)
94.3
(86.0,102.7)
111.4
(101.3,121.5)
51-70 580 68.9
(66.3,71.5)
31.8
(25.6,37.9)
40.8
(36.0,45.6)
51.7
(47.6,55.8)
68.4
(63.7,73.1)
84.2
(80.4,88.1)
99.3
(93.3,105.2)
107.1
(100.8,113.4)
71-79 182 77.8
(72.6,83.0)
34.8
(28.3,41.3)
44.9
(36.6,53.3)
61.7
(56.1,67.3)
74.7
(64.3,85.1)
94.2
(85.1,103.4)
111.2
(102.4,120.0)
116.4
(109.1,123.8)
19-79 1887 69.5
(67.4,71.6)
32.0
(28.9,35.2)
39.4
(36.0,42.8)
50.9
(47.8,53.9)
67.4
(65.0,69.8)
83.9
(82.6,85.2)
101.9
(98.3,105.5)
113.4
(107.2,119.5)

Note:

Total household population aged 9 to 79, except those meeting the exclusion criteria.  For more information regarding the exclusion criteria, please refer to the  Canadian Health Measures Survey (CHMS) Data User Guide: Cycle 1.

Bootstrap weights included with the dataset were used to estimate the 95% confidence intervals for all means and percentiles assuming a student's t-distribution with 11 degrees of freedom.

Plasma 25(OH)D levels were measured by a chemiluminescence immunoassay using the LIAISON 25-Hydroxyvitamin D TOTAL assay (Diasorin, Ltd.).

Measurements that fell below the limit of detection (LOD) were assigned a value equal to half the LOD.  The limit of detection is 10 nmol/L.

Data source: Canadian Health Measures Survey, Cycle 1.

Related resources

Chapter on  Vitamin D in Dietary Reference Intakes for Calcium and Vitamin D (2011)

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