Reindeer meat contained higher vitamin B12, Fe, Zn and Se concentrations when compared to Norwegian beef, lamb, mutton, pork and chicken meat [
4]. The geographical differences revealed in this study were not large and will most likely have no impact for consumers. Vitamin E and Selenium demonstrated relatively large geographical variations. Calves had a significant lower Zn concentration than young and older animals, whereas young animals had a significant lower Se concentration than calves and older animals. Positive correlations were revealed between iron and calcium, and vitamin B12 and zinc. Animals originating from districts with low animal population density had on average higher selenium concentration than those from districts with medium and high population densities.
4.1. Concentrations and Geographical Variations
Reindeer meat contained a concentration of vitamin B12 that is nearly four, five, nine and twelve times higher than those of lamb meat, beef, pork and chicken, respectively. Iron concentration in reindeer meat was two times higher than that of lamb meat and beef, and four times higher than that of pork and chicken. Furthermore, Zinc concentration was two times higher than that of beef, three times higher than that of lamb and pork, and five times higher than that of chicken, whereas selenium concentration was two times higher than that of pork and chicken, seven times than that of lamb and five times than that of beef [
4].
Vitamin A was detected in only one pooled sample originating from Essand/Røros. Vitamin E and selenium were the nutrients that demonstrated the largest geographical variations, whereas no geographical differences were found for vitamin B7, calcium and iron concentrations. Calves (10 months) had a significant lower Zn concentration than young (1.5 years) and older animals (>2 years), whereas young animals had a significantly lower Se concentration than calves and older animals. Iron was positively correlated with calcium, and vitamin B12 was positively correlated with zinc. Districts with medium and high animal population density (3–5.3 and 6–13.7 animals/km2, respectively) had an average 12.4 µg/100 g raw meat lower selenium than those with low population density (0.8–1.9 animals/km2).
Concentration of vitamin A detected from the pooled sample originating from Essand (Røros) in this study (5.7 µg/100 g) was comparable to that reported from reindeer meat in Finland, two times higher than that from Sweden and four times lower than those previously reported from Norway [
2,
17,
18,
19]. Furthermore, vitamin A concentration reported from Arctic Canadian caribou (93.5 µg/100 g ww) was much higher than the concentration detected in the present study [
20].
The concentration of vitamin B3 detected in this study (6.6 mg/100 g) was comparable to that found in US caribou, slightly higher than that previously reported from Norway (4.3 mg/100 g) and slightly lower than that reported from Finland (8.6 mg/100 g) and from Canadian caribou, 10.9 mg/100 g [
2,
18,
21,
22]. No data on vitamin B7 in meat from reindeer or caribou were available for comparison other than that of 1.2 µg/100 g from Norway which was two times higher than the value of 0.6 µg/100 g detected in the present study [
2]. Vitamin B12 concentration of 4.7 µg/100 g detected in the present study was comparable to that previously reported from Norway (3.3 µg/100 g) and slightly lower that of 6.31 µg/100 g reported from US caribou [
2,
21]. Additionally, vitamin B12 concentration in reindeer meat was found to be higher when compared to concentrations in meat from other ruminant animals (e.g., mutton and beef) [
2,
3,
4]. This could be due to reindeer feeding on lichens as lichens have previously been found to improve microbial activity in reindeers’ rumens [
23].
Concentration of vitamin E (α-tocopherol) detected in the present study (0.5 mg/100 g) was comparable to that previously reported in reindeer meat from Norway and Sweden, lower than that of 0.84 mg/100 g reported from Finland and higher than that of 0.15 mg/100 g reported from Arctic Canada [
2,
18,
19,
20,
24].
Calcium concentration of 4.7 mg/100 g detected in this study was comparable to that reported from Norway, Finland, and Arctic Canada [
2,
18,
25]. However, Ca concentration of 17 mg/100 g previously reported from US caribou was nearly four times higher than the one detected in the present study [
21].
Iron concentration in the present study was comparable to that of 3.3 and 3 mg/100 g formerly reported from Norway and Finland, respectively [
2,
18]. However, Fe concentration from this study was nearly 50% lower than that reported from Russian reindeer, Arctic Canadian and US caribou [
21,
25,
26]. The highest Fe concentration of 4.6 mg/100 g measured in this study agreed well with that newly reported from a Norwegian study on reindeer meat by Triumf and colleagues [
24]. Zinc concentration detected in the present study was in agreement with that previously reported from Norway and nearly two times higher than values reported from Greenlandic reindeer, Arctic Canadian and US caribou [
2,
21,
25,
27].
Selenium concentration in the present study was characterized by a wide range (7.1–51.5 µg/100 g). This was due to geographical variation in Se concentration which has also been demonstrated in our previous study on meat, liver, tallow and bone marrow from reindeer [
2]. Se concentration detected in this study was comparable to that reported from Finland (24 µg/100 g), twice that of 10.2 µg/100 g reported from US caribou and much higher than that of 3 µg/100 g reported from a previous Norwegian study [
2,
17,
18,
21]. Furthermore, Se concentrations from Greenlandic reindeer ranged from 0.3 to 2.52 µg/100 g while Canadian Arctic caribou revealed much lower concentration (0.01 µg/100 g) [
25,
27]. No data were available for comparison regarding Cr and Co concentrations in meat from reindeer and caribou. However, Sivertsen and colleagues have reported Cr concentration of 2 µg/100 g and Co concentrations ranged from 7 to 11 µg/100 g from reindeer liver in Norway [
28]. Similar Co concentrations as detected by Sivertsen
et al. and a higher Cr (8 µg/100 g) have been detected from Russian reindeer liver [
29].
Reindeer meat contained higher vitamin B12, Fe, Zn and Se concentrations when compared to Norwegian beef, lamb, mutton, pork and chicken meat [
4]. Carcass cuts had been taken into consideration when the previously mentioned comparison was done. This was conducted either by using the same carcass cut (e.g., neck cutlets) or using cuts that are anatomically relevant to neck muscles (e.g., saddle muscles). The geographical differences for nutrient concentrations revealed in the present study were generally not large and will most likely have no impact for consumers. The evaluation of the vitamin and essential element concentrations in terms of high or low should be looked at in the light of the recommended dietary intake/allowance (RDI/RDA) values for each vitamin or essential element as set by the Nordic Council of Ministers/the US National Research Council [
30,
31].
The wide Se concentration range (µg/100 g raw reindeer meat) in the present study contributes to 18%–100% and 14%–100% of the RDI for adult women and men, respectively. Furthermore, the detected Zn range contributes to 38%–157% and 29%–122% for women and men, respectively. The detected vitamin B12 range of 1.7–8.8 µg/100 g raw reindeer meat contributes to 85%–440% of the RDI for both women and men. There are no established RDI/RDA for vitamin B7, cobalt and chromium. However a US recommendation for vitamin B7 of 30 µg per day was set as an adequate intake (AI) for adults [
32]. Furthermore, chromium concentrations of 25 and 35 µg/day have been reported as adequate intakes (AI) for young women and men, respectively [
33].
Vitamin B12 synthesis in ruminant animals (e.g., reindeer) depends on the presence of cobalt [
34]. Hence, we were expecting vitamin B12 to correlate positively with cobalt, but such correlation was not observed in the present study.
4.3. Pooled Vitamin Samples
Due to the presence of some pooled vitamin samples with mixed age groups (
n = 8 pooled samples) from some districts (
n = 4 districts), additional statistical analyses were performed in order to see whether age had an effect on vitamin concentrations or not before we could join all data together prior to the statistical analyses. This was done by dividing data into two sets; one with districts (
n = 6 districts) that had homogenized age group (
n = 60 animals) and the other with those (
n = 4 districts) with mixed age group (
n = 40 animals). We carried out the same statistical analyses as described in the statistical analysis part on both data sets and no effect for age on vitamin concentrations could be observed (results not presented). However, reindeer calves had previously been reported to have higher (7%–10%) vitamin concentrations than those of adult reindeer [
17,
36]. Advantages and disadvantages of pooled samples were discussed elsewhere [
2]. The ideal situation in case of pooled samples is that samples need to originate from the same districts and consist of homogenized age and sex groups. However, looking into differences in vitamin concentrations within districts would not be possible in such a case as concentrations of pooled samples were based on the mean of the individual samples from which the pooled sample consisted (
i.e., not obtained from individual concentrations separately).