Reciprocal seasonal variation in vitamin D status and tuberculosis notifications in Cape Town, South Africa

Martineau, Adrian R.; Nhamoyebonde, Shepherd; Oni, Tolu; Rangaka, Molebogeng X; Marais, Suzaan; Bangani, Nonzwakazi; Tsekela, Relebohile; Bashe, Lizl; Azevedo, Virginia De; Caldwell, Judy; Venton, Timothy R; Timms, Philip; Wilkinson, Katalin A.; Wilkinson, Robert J.

doi:10.1073/pnas.1111825108

Cited by 185 publications

(222 citation statements)

References 33 publications

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“…Martineau et al (1) found that there is a significant association of vitamin D deficiency with susceptibility to TB and that the impact is greater in HIV-infected than noninfected individuals. In addition, Martineau et al…”

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Shedding light on the vitamin D–tuberculosis–HIV connection

Realegeno

Modlin²

2011

Proc. Natl. Acad. Sci. U.S.A.

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T he paper in PNAS by Martineau et al.(1) raises a key public health issue: how much vitamin D do you need to fight tuberculosis (TB)? Martineau et al. (1) found that there is a significant association of vitamin D deficiency with susceptibility to TB and that the impact is greater in HIV-infected than noninfected individuals. In addition, Martineau et al.(1) discover a striking temporal relationship between vitamin D deficiency and TB. The reporting of new TB cases in Cape Town, South Africa, was lowest in the months after the seasonal increase in serum 25-hydroxyvitamin D (25D) levels, whereas the reporting of new TB cases was highest in the months following the season with the lowest serum 25D levels.The major source of vitamin D for humans derives from sun exposure; in the skin, UVB induces conversion of 7-dehydrocholesterol to previtamin D3 and then vitamin D3 (cholecalciferol). In the liver, vitamin D3 is 25-hydroxylated to form 25D. 25D is then converted in the kidney by the 1-α-hydroxylase, CYP27b1, to 1,25-dihydroxyvitamin D (1,25D), the bioactive, hormonal form of vitamin D that is bound with high affinity and specificity by the vitamin D receptor (VDR). Serum 1,25D levels are maintained in a constant range by parathyroid hormone regulation of the CYP27b1 gene. Therefore, circulating levels of 25D are the best clinical assessment of adequate vitamin D status. Some of the factors that determine 25D levels include latitude (25D levels can be maintained year round in the equatorial regions between the Tropic of Cancer and Tropic of Capricorn), skin color (10 times as much UVB is required to produce the same amount of vitamin D in dark-vs. lightskinned individuals), outdoor activity, body surface exposed, oral supplementation, and SNPs in several vitamin D metabolism genes.Martineau et al.(1) also report that vitamin D deficiency is present in greater than 60% of a population of active and latent TB patients in Cape Town, South Africa. The frequency of vitamin D deficiency is higher than anticipated but may be, in part, expected because of at least three risk factors in the study population: (i) they are black; (ii) they reside in Capetown (33°S latitude), which is well south of the Tropic of Capricorn; and (iii) they are poorly nourished in terms of oral vitamin D supplementation. Although vitamin D status has been previously suggested as a contributing factor to the incidence of TB, a relationship between seasonal vitamin D status and TB case notification has not previously been evaluated in the same population.A number of investigations have linked serum 25D levels to both TB disease susceptibility and progression. Meta-analysis of observational studies suggested a 70% probability that a healthy individual would have higher 25D serum levels than an individual with untreated TB. Nnoaham and Clarke (2) concluded that "it is more likely that low body vitamin D levels increase the risk of active tuberculosis."The association of low 25D levels with TB raises two questions. (i) If 1,25D is the bioactive form...

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confidence: 99%

“…T he paper in PNAS by Martineau et al (1) raises a key public health issue: how much vitamin D do you need to fight tuberculosis (TB)? Martineau et al (1) found that there is a significant association of vitamin D deficiency with susceptibility to TB and that the impact is greater in HIV-infected than noninfected individuals.…”

mentioning

confidence: 99%

Shedding light on the vitamin D–tuberculosis–HIV connection

Realegeno

Modlin²

2011

Proc. Natl. Acad. Sci. U.S.A.

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“…It is not self-evident, though, that these results can be transferred to HIV-infected subjects: for patients on anticonvulsant drugs (which are considered to interfere similarly to ART [1]) and patients with hyperparathyroidism (which was found to occur secondary to ART with tenofovir disoproxil fumarate [5,6]) a loss of seasonality has been described [7,8]. Although a seasonal difference has been hinted at in some small or highly selective HIV-infected populations [9][10][11][12], detailed information is sparse. Yet, knowledge about seasonality is essential for interpretation of laboratory results of vitamin D concentrations.…”

Section: Seasonal Variations In Vitamin D Levels In Hiv-infected Patimentioning

confidence: 99%

Seasonal variations in vitamin D levels in HIV-infected patients

Noe¹,

Heldwein²,

Pascucci³

et al. 2017

HIV & AIDS Review

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Introduction: Human immunodeficiency virus (HIV)-infected patients treated with antiretroviral therapy (ART) are at high risk for vitamin D insufficiency, which is essentially caused by interference of medication with vitamin D metabolism. Under these conditions, the preservation of natural seasonal variability in vitamin D concentrations is not self-evident. Yet, for proper screening and interpretation of laboratory findings, knowledge about seasonality is essential. Aim of the study was to describe seasonal behavior in ART-treated HIV-infected patients in Central Europe. Material and methods:It was a retrospective single-center study. Patients' medical records were screened for serum vitamin D levels, β-crosslaps, and surrogate values of bone turnover.Results: A total of 1011 datasets (625 patients) were evaluated. Overall, the median vitamin D level was 19.6 µg/l. In 207 (16.4%) datasets, patients were receiving oral cholecalciferol supplementation. Seasonal changes in serum vitamin D levels were reflected by minimum levels (median 13.5 µg/l) in March and maximum levels (median 23.7 µg/l) in July (p < 0.001). In contrast, serum calcium levels were lowest in September and October (2.23 mmol/l) and highest in May (2.32 mmol/l). Conclusions:Significant variation in seasonal serum vitamin D levels was found in an unselected population of HIV-infected patients. This finding is in line with results from HIV-negative populations. Accordingly, the time point of vitamin D testing might be crucial for appropriate diagnosis of hypovitaminosis. We recommend vitamin D testing between December and May to provide the highest sensitivity. As serum calcium levels did not demonstrate the same pattern, the meaning of this finding is unclear and warrants further investigation.

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“…2 Vitamin D deficiency, for example, was reported in 2011 to be extremely common in black Africans living in Cape Town, and it was associated with susceptibility to tuberculosis (TB) infection. 3 It was concluded that vitamin D supplementation may be a highly cost-effective, safe and simple means to reduce TB incidence. 3 In a study recently reported by Busse et al, 4 the negative impact of vitamin D deficiency on bone health, specifically the higher risk for bone fractures was demonstrated; however, its impact on other health areas is less clear.…”

Section: Introductionmentioning

confidence: 99%

“…3 It was concluded that vitamin D supplementation may be a highly cost-effective, safe and simple means to reduce TB incidence. 3 In a study recently reported by Busse et al, 4 the negative impact of vitamin D deficiency on bone health, specifically the higher risk for bone fractures was demonstrated; however, its impact on other health areas is less clear. Vitamin D deficiency has been suggested, for example, to play a role in depression 5 and has also been associated with increased HIV-1 replication in HIV-infected individuals.…”

Section: Introductionmentioning

confidence: 99%

Dispensing of vitamin products by retail pharmacies in South Africa: Implications for dietitians

Truter

Steenkamp

2016

South African Journal of Clinical Nutrition

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Objective: The objective of this study was to analyse the dispensing patterns of vitamins (Anatomical Therapeutic Chemical (ATC) group A11) over a one-year period in a group of community pharmacies in South Africa. Design and setting: A retrospective drug utilisation study was conducted on community pharmacy electronic dispensing records in South Africa recorded in 2013. Outcome measures: All products for ATC subgroup A11 were extracted and analysed. Results: A total of 164 233 vitamin products were dispensed to 84 805 patients (62.64% female patients). Males received on average 2.09 (SD = 2.63) vitamin products per year, compared to 1.84 (SD = 2.13) products for females. Ergocalciferol (A11CC01) was the most often dispensed (37.48% of all vitamin products), followed by plain Vitamin B-complex products (A11EA00) accounting for 32.77%. Ergocalciferol (vitamin D2) is only available on prescription (50 000 IU tablets or 50 000 IU/ml oily drops) in South Africa. Tablets were the preferred dosage form (62.84% of products). Most injections were for Vitamin B1 or Vitamin B combination products. Conclusion: Ergocalciferol and injectable vitamins have recently been rescheduled to prescription-only; it is probable that this has impacted on the usage of these products. It is important to monitor future vitamin supplementation behaviour in community pharmacies since pharmacies are selling many of these products and pharmacists can, by counselling patients, determine the reasons for the use of these products. Furthermore, should dietitians and nutritionists choose to work with this captive audience, supplementation patterns can be monitored to develop and implement appropriate awareness campaigns. Further studies to explore these baseline results are recommended.

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Reciprocal seasonal variation in vitamin D status and tuberculosis notifications in Cape Town, South Africa

Cited by 185 publications

References 33 publications

Shedding light on the vitamin D–tuberculosis–HIV connection

Shedding light on the vitamin D–tuberculosis–HIV connection

Seasonal variations in vitamin D levels in HIV-infected patients

Dispensing of vitamin products by retail pharmacies in South Africa: Implications for dietitians

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