“Ought to I take vitamin D?” Right here’s what the science says.

23 0
“Should I take vitamin D?” Here’s what the science says.

What is V.Itamin D? | How much do you need? | Vitamin D and the sun | Food sources | Best addition | Deficiency | Nutritional interactions | Vitamin D and Immunity

Vitamin D is starting to sound, well, too good to be true.

Hundreds of research studies suggest that vitamin D can help prevent everything from osteoporosis to autoimmune diseases, cardiovascular disease, and cancer

Doctors recommend it. Health podcasters talk about it. Even your mom annoys you about it.

With all the hype, a lot of people are asking:

"Should I take vitamin D?"

We have your answers.

In this article, we'll show you how to find out if vitamin D supplementation is right for you.

You will learn why it matters to your health, how much you need, and what you need to know before thinking about taking a vitamin D supplement.

Oh, and when you finish reading you can send this article to mom. (And do it our best, right?)

What is Vitamin D

Vitamin D is a fat-soluble vitamin that we get (mostly) from the sun, but also from certain foods and of course from dietary supplements.

In fact, "Vitamin D" isn't just one thing. Vitamin D refers to a group of compounds.

Let's meet with the family:

  • Vitamin D2 (ergocalciferol) can be made by plants (such as mushrooms) and yeasts.
  • Vitamin D3 (cholecalciferol) comes from animal products such as fish, egg yolks and cheese. We also produce vitamin D3 on the surface of our skin when we are exposed to sunlight.
  • Calcifediol (25-hydroxyvitamin D) is the form of vitamin D that is measured in blood tests. It actually starts out as vitamin D3, but once vitamin D3 gets into your bloodstream, your liver converts it to calcifediol.
  • Calcitriol (1.25 dihydroxyvitamin D) is the most metabolically active form of vitamin D. It is made from calcifediol in your kidneys. In contrast to its precursor vitamin D3, calcitriol is no longer considered a vitamin: it is a hormone.

Whoa. So much shape change. Sneaky.

What does vitamin D do?

Recent research suggests that almost every cell in our body has receptors for vitamin D. Unsurprisingly, it has far-reaching effects on the body.

Vitamin D supports your:

  • immune system
  • Cell function
  • Blood sugar regulation
  • Bone health
  • Calcium absorption and circulation
  • normal blood pressure

(Did you know that most vitamins and minerals have far-reaching health effects? Learn more: All About Vitamins and Minerals.)

How do I know if I need to add?

For many of us, supplementing with vitamin D is a good idea. Especially if we fall into one of the categories of people who are more likely to be vitamin D deficient. ((Take the quiz below to find out if it's you.)

The only way to be sure we have a deficiency is to do a blood test.

To optimize bone health and minimize the risk of disease, people should try to achieve a vitamin D blood level of at least 50 nmol / l (20 ng / ml) .2 (The “sweet spot” could be closer to the environment 75 nmol / l or 30 ng / ml.)

In order to achieve this goal, the recommended daily vitamin D intakes (from combined foods and dietary supplements) for different phases of life are listed here:

General recommendations for the intake of vitamin D.

Age Recommended daily vitamin D intake
0-12 months 400-1000 IU / day
1–18 years 600-1000 IU / day
18–70+ years 800-2000 IU / day
Pregnant / breastfeeding (> 18 years) 800-2000 IU / day

Most healthy adults should be able to maintain adequate levels of vitamin D in the blood (50-100 nmol / L or 20-40 ng / ml) by getting around 800-1000 IU of vitamin D daily from foods and supplements .

In cases of more severe deficiency, some people may need to take more vitamin D than we have listed above. Work with your doctor to find out what dose is right for you and how long to take it.

How do you get vitamin D?

The best source of vitamin D ever: the sun

Many people can get their vitamin D needs from sunshine alone. And for “natural sources of vitamin D,” sunlight is a good choice.

A good general guideline is to take around 10 to 20 minutes a day in the midday sun with your face, arms, hands, and legs uncovered (and no sunscreen).

The amount of vitamin D you get (and absorb) from the sun depends on a number of factors, including geographic location, skin tone, clothing style, sunscreen use, age, and general health.

Depending on who you are and where you are, you may need more sun than the above recommendation.

The Best Vitamin D Food Sources

You can significantly increase your vitamin D intake by prioritizing certain foods in your diet.

Here are some of the best sources3:

The table is divided into two columns: The left column is labeled "Food" and contains a list of foods rich in vitamin D. The right column is labeled "Vitamin D content" and shows the amount of vitamin D (in international units and micrograms) in each food. The food choices are listed in order of the highest to lowest amount of vitamin D. Starting from the top row, the list is: 3 ounces of cooked rainbow trout contains 645 IU or 16.2 µg of vitamin D. 3 ounces of cooked sockeye salmon contains 570 IU or 14.2 µg of vitamin D. 1 cup of 2% vitamin D fortified milk contains 120 IU or 2.9 µg of vitamin D. 1 cup of soy, almond or oat milk fortified with vitamin D contains 100 to 144 IU or 2.5 to 3.6 mcg of vitamin D. 2 cans of sardines - drained - contain 46 IU or 1.2 mcg of vitamin D. 1 large boiled egg with egg yolk contains 44 IU or 1.1 µg of vitamin D. 3 ounces of braised beef liver contains 42 IU or 1 µg of vitamin D. 3 ounces of canned light tuna - drained - contains 40 IU or 1 µg of vitamin D. 1 ounce of cheddar cheese contains 12 IU or 0.3 µg of vitamin D.

The best vitamin D supplement

Vitamin D supplements can come in pill, liquid, sublingual spray, or (yes) chewable gum worm.

While the method of delivery of the dietary supplement isn't that important4, the form of the vitamin D in it is what matters.

You can usually find two forms of vitamin D in pharmacies and health food stores:

  • Vitamin D2, obtained from yeast or mushrooms (and vegan-friendly)
  • Vitamin D3, typically obtained from lanolin (from sheep's wool)

While both forms can increase vitamin D levels in the blood, vitamin D3 seems to optimize vitamin D levels better and to maintain these levels in the longer term.5,6,7

So, unless you are avoiding animal products, look for a supplement that contains vitamin D3 (cholecalciferol).

However – and this is important – taking vitamin D when not deficient has little to no benefit – and can even cause harm

(Further information on assessing your risk of deficiency can be found below.)

The interaction between vitamin D, calcium and other nutrients

Meet the "colleagues" of vitamin D.

The following nutrients support the role of vitamin D in the body and mutually benefit from the presence of vitamin D.

  • Calcium is better absorbed in the presence of vitamin D. This is one of the reasons why vitamin D is important for bone health. However, if you take too much of either, calcium can build up in places it doesn't belong to: soft tissues like the kidneys and arteries
  • Vitamin K helps direct calcium to where it belongs (mostly in the bones) .10 Taking vitamin K with vitamin D can prevent calcium from building up in soft tissues.11,12,13
  • Magnesium can help convert vitamin D into its more metabolically active forms. Research shows that taking magnesium with vitamin D is more effective in correcting vitamin D deficiency than vitamin D supplementation alone.14,15
  • Vitamin A can prevent the toxicity of vitamin D and vice versa.3 Some studies also suggest that increasing vitamin A may decrease the calcium build-up that can occur with higher vitamin D levels.16

There is one caveat here: taking high doses of vitamin D along with high doses of any of these vitamins and minerals can in some cases backfire and lead to health problems. (Especially if you have other nutritional deficiencies.)

While dietary supplements are very unlikely to be overdosed, dietary supplements can allow a mega dose and this is where potential problems can arise.

If you're not sure how to balance your supplements, talk to your doctor.

Vitamin D deficiency

Most experts agree that a blood level of:

  • 30-50 nmol / l (12-20 ng / ml) 25-hydroxyvitamin D3 or 25 (OH) D are not enough for optimal health
  • <30 nmol / l (12 ng / ml) 25 (OH) D is considered a severe deficiency

Values ​​in both areas are likely to benefit from supplementation.17,18,19

How common is vitamin D deficiency?

According to statistics, between 20 and 40 percent of adults and children worldwide do not have enough vitamin D.19,20,21

Here's a fun quiz (fun for health nerds like us):

If you answer "yes" to any of the following questions, you are at increased risk of vitamin deficiency.

Do you:

  • Live far away from the equator and / or experience winter? It is almost impossible to get enough vitamin D from sunlight during certain times of the year – usually the colder months – even if you spend a lot of time outdoors
  • Do you have darker skin? Melanin – the pigment that darkens the skin – decreases the skin's ability to produce vitamin D when exposed to sunlight.17 In the US, 89 percent of blacks and 69 percent of Hispanics are deficient in vitamin D.23
  • Fall into the “50+” age category? Age decreases the body's ability to synthesize vitamin D on the skin. 24
  • Do you have a chronic illness, malabsorption problems, or a BMI that classifies you as "obese"? People with certain diseases, malabsorption, or obesity don't necessarily have problems producing vitamin D on their skin, but they are more likely to have problems absorbing and metabolizing it.25,26
  • Do you tend to cover up when you go outside (either with clothes or sunscreen)? Wearing clothing that covers most of your body – for religious, stylistic, or health reasons – or wearing sunscreen will protect your skin from UVB and UVA light and block the synthesis of vitamin D. Burn survivors or skin cancer survivors can be particularly susceptible to SPF.
  • Just not going outside much (in daylight)? Whether due to illness or shift work, if you can't go outside at sunrise, you're missing the window for optimal vitamin D synthesis.

Diseases related to vitamin D deficiency

As you can imagine, the worse a deficiency, the worse the negative health effects.

More extreme vitamin D deficiencies dramatically increase the risk of premature death, infection, and many other diseases.27

Some diseases associated with vitamin D deficiency:

  • Osteoporosis and general weakening or softening of the bones26
  • Immune weaknesses such as autoimmune diseases and increased susceptibility to infections28
  • Type 2 diabetes 29.30
  • Cardiovascular diseases31,32
  • Cancer, especially cancer mortality33,34,35
  • Obesity36
  • Depression37

The problem is, we don't have strong evidence that improving vitamin D status on its own will reverse or improve these conditions. We also don't know for sure whether vitamin D deficiency or insufficiency is actually the cause of them.

Although vitamin D deficiency has been linked to these conditions, we're still trying to figure out how.

Vitamin D and Immunity

Vitamin D has been touted as an immune booster for years.

As a result, it becomes a popular just in case addition during flu season, and especially during the COVID-19 pandemic.

But remember, as we said, supplementing vitamin D is unlikely to benefit you if you are not deficient?

This also applies to the immune function.

If you take extra vitamin D at normal levels, you will not get “superimmunity”.

It is true that vitamin D deficiency is linked to more common and more severe infections such as upper respiratory diseases, 38 and COVID-19.39,40

So yes, if you are concerned about your immune health and suspect you may be vitamin D deficient, get tested.

If you have a confirmed deficiency, take these D values ​​within a normal range: 50-100 nmol / L (20-40 ng / ml) of 25 (OH) D.

(Your doctor can help you figure out the right dose of vitamin D and how long to take it.)

However, if your vitamin D levels are normal, there is no need for supplementation.

Learn more: 8 ways to optimize your immunity and protect your health.

Vitamin D: Your Next Steps

1. If possible, get (safe) sun exposure and eat foods rich in vitamin D.

The vitamin D needs of many people can and should be met through exposure to sunlight and diet alone.

Eat foods rich in vitamin D along with a variety of colorful fruits and vegetables that are rich in vitamins and minerals – such as calcium, magnesium, vitamin K, and vitamin A – that help vitamin D work in the body.

As a coach, it is best to adhere to food and lifestyle practices to help your clients meet their vitamin D needs, unless you have a different label for practicing Medical Nutritional Therapy (MNT). qualified.

Trainers can educate clients about their risk factors or set general guidelines for vitamin D intake, but only qualified MNT doctors can diagnose and treat deficiencies.

2. If you suspect a deficiency, get a blood test.

If possible, get a blood test to confirm any suspected deficiencies. (This also applies to other nutrients – such as iron or vitamin B12 – not just vitamin D.)

And remember, when consuming high doses of vitamin D, we should be wary of other deficiencies.

Consult a doctor to determine if there is a deficiency and, if so, what dose to take to correct the deficiency.

3. Pay attention to those who are more prone to defects.

If you have a customer who:

  • has malabsorption problems
  • has darker skin
  • lives far from the equator
  • covered up (either with clothes or sunscreen)

… Know that vitamin D deficiency is common. 20

And most people with low vitamin D levels won't "feel" it.

While some may get colds or fluids more frequently, 41 many people have no symptoms at all.

If a customer falls into one or more of the risk categories (especially if their diet is also low in vitamin D), suggesting that they work with a doctor and get tested.

Bottom line: Even if something is important to our health – like vitamins, minerals, water and, let's say, a good supply of toilet paper – more is not always better.

jQuery (document) .ready (function () {
jQuery ("# ​​reference_link"). click (function () {
jQuery ("# ​​reference_holder"). show ();
jQuery ("# ​​reference_link"). parent (). hide ();
});
});

References

Click here to view the resources referenced in this article.

1. Schottker B., Haug U., Schomburg L. et al. Strong associations of 25-hydroxyvitamin D concentrations with all-cause mortality, cardiovascular, cancer, and respiratory diseases in a large cohort study. At J Clin Nutr. 2013 Apr; 97 (4): 782- 93.

2. Kimball, Samantha M., and Michael F. Holick. 2020. “Official Recommendations for Vitamin D During Life Phases in Developed Countries.” European Journal of Clinical Nutrition 74 (11): 1514–18.

3. "Vitamin D." n.d. Accessed March 29, 2021. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/.

4. Grammatikopoulou, Maria G., Konstantinos Gkiouras, Meletios P. Nigdelis, Dimitrios P. Bogdanos and Dimitrios G. Goulis. 2020. "Effectiveness of Buccal Vitamin D3 Spray Supplement Compared to Other Delivery Methods: A Systematic Review of Randomized Controlled Superiority Studies." Nutrients 12 (3). https://doi.org/10.3390/nu12030691.

5. Tripkovic, Laura, Helen Lambert, Kathryn Hart, Colin P. Smith, Giselda Bucca, Simon Penson, Gemma Chope et al. 2012. “Comparison of Vitamin D2 and Vitamin D3 Supplementation in Increasing Serum 25-Hydroxyvitamin D Status: A Systematic Review and Meta-Analysis.” The American Journal of Clinical Nutrition 95 (6): 1357-64.

6. Logan, Victoria F., Andrew R. Gray, Meredith C. Peddie, Michelle J. Harper, and Lisa A. Houghton. 2013. "Long-term vitamin D3 supplementation is more effective than vitamin D2 in maintaining serum 25-hydroxyvitamin D status over the winter months." The British Journal of Nutrition 109 (6): 1082-88.

7. Vieth, Reinhold. 2020. "Vitamin D Supplementation: Cholecalciferol, Calcifediol, and Calcitriol." European Journal of Clinical Nutrition 74 (11): 1493-97.6

8. Khan, Safi U., Muhammad U. Khan, Haris Riaz, Shahul Valavoor, Di Zhao, Lauren Vaughan, Victor Okunrintemi et al. 2019. "Effects of Dietary Supplements and Dietary Interventions on Cardiovascular Outcomes: An Umbrella Review and Evidence Map." Annals of Internal Medicine 171 (3): 190-98.

9. Michos, Erin D., Miguel Cainzos-Achirica, Amir S. Heravi, and Lawrence J. Appel. 2021. "Vitamin D, Calcium Supplements, and Implications for Cardiovascular Health: JACC Focus Seminar." Journal of American College of Cardiology 77 (4): 437-49.

10. Ushiroyama, Takahisa, Atushi Ikeda and Minoru Ueki. 2002. "Effect of continuous combined therapy with vitamin K (2) and vitamin D (3) on bone mineral density and coagulofibrinolytic function in postmenopausal women." Maturitas 41 (3): 211-21.

11. Shea, M. Kyla, and Rachel M. Holden. 2012. "Vitamin K Status and Vascular Calcification: Evidence from Observational and Clinical Studies." Advances in Nutrition 3 (2): 158–65.

12. Shea, M. Kyla, Christopher J. O'Donnell, Udo Hoffmann, Gerard E. Dallal, Bess Dawson-Hughes, José M. Ordovas, Paul A. Price, Matthew K. Williamson, and Sarah L. Booth. 2009. "Vitamin K Supplementation and Coronary Artery Calcium Progression in Older Men and Women." The American Journal of Clinical Nutrition 89 (6): 1799-1807.

13. Masterjohn, Christopher. 2007. "Vitamin D Toxicity Redefined: Vitamin K and the Molecular Mechanism." Medical Hypotheses 68 (5): 1026–34.

14. Deng, Xinqing, Yiqing Song, Joann E. Manson, Lisa B. Signorello, Shumin M. Zhang, Martha J. Shrubsole, Reid M. Ness, Douglas L. Seidner, and Qi Dai. 2013. "Magnesium, Vitamin D Status, and Mortality: Results of the US National Health and Nutrition Examination Survey (NHANES) 2001-2006 and NHANES III." BMC Medicine 11 (August): 187.

15. Uwitonze, Anne Marie, and Mohammed S. Razzaque. 2018. "Role of Magnesium in Activation and Function of Vitamin D." The Journal of the American Osteopathic Association 118 (3): 181-89.

16. Johansson, S. and H. Melhus. 2001. "Vitamin A antagonizes the calcium response to vitamin D in humans." Journal of Bone and Mineral Research: The Official Journal of the American Society for Bone and Mineral Research 16 (10): 1899-1905.

17. Institute of Medicine (US) Committee to Review Dietary Intake for Vitamin D and Calcium. 2011. Dietary intake for calcium and vitamin D. Edited by Catharine A. Ross, Christine L. Taylor, Ann L. Yaktine, and Heather B. Del Valle. Washington (DC): National Academies Press (USA).

18. Holick, Michael F., Neil C. Binkley, Heike A. Bischoff-Ferrari, Catherine M. Gordon, David A. Hanley, Robert P. Heaney, M. Hassan Murad, Connie M. Weaver, and Endocrine Society. 2011. "Assessment, Treatment, and Prevention of Vitamin D Deficiency: An Endocrine Society Clinical Practice Guideline." The Journal of Clinical Endocrinology and Metabolism 96 (7): 1911-30.

19. Amrein, Karin, Mario Scherkl, Magdalena Hoffmann, Stefan Neuwersch-Sommeregger, Markus Köstenberger, Adelina Tmava Berisha, Gennaro Martucci, Stefan Pilz and Oliver Malle. 2020. "Vitamin D Deficiency 2.0: An Update on Current Status Worldwide." European Journal of Clinical Nutrition 74 (11): 1498–1513.

20. Parva, Naveen R., Satish Tadepalli, Pratiksha Singh, Andrew Qian, Rajat Joshi, Hyndavi Kandala, Vinod K. Nookala, and Pramil Cheriyath. 2018. "Prevalence of vitamin D deficiency and associated risk factors in the US population (2011-2012)." Cureus 10 (6): e2741.

21. Cashman, Kevin D., Tony Sheehy, and Colette M. O & # 39; Neill. 2019. “Is Vitamin D Deficiency a Public Health Problem in Lower Middle Income Countries? A systematic review of the literature. "European Journal of Nutrition 58 (1): 433-53.

22. Wacker, Matthias, and Michael F. Holick. 2013. “Sunlight and Vitamin D: A Global Perspective for Health.” Dermato-Endocrinology 5 (1): 51-108.

23. Forrest, KY, Stuhldreher, WL. Prevalence and Correlates of Vitamin D Deficiency in Adults in the United States. Nutr Res. 2011 Jan; 31 (1): 48-54.

24. Chalcraft, Jenna R., Linda M. Kardinal, Perry J. Wechsler, Bruce W. Hollis, Kenneth G. Gerow, Brenda M. Alexander, Jill F. Keith, and D. Enette Larson-Meyer. 2020. "Vitamin D synthesis after single exposure to the sun in older and younger men and women." Nutrients 12 (8). https://doi.org/10.3390/nu12082237.

25. Silva, Mariana Costa and Tania Weber Furlanetto. 2018. "Intestinal Absorption of Vitamin D: A Systematic Review." Nutrition Reviews 76 (1): 60-76.

26. Institute of Medicine, Food and Nutrition Committee, and Committee to Review Reference Intake for Vitamin D and Calcium. 2011. Dietary intake for calcium and vitamin D. National Academies Press.

27. Wang, Hanmin, Weiwen Chen, Dongqing Li, Xiaoe Yin, Xiaode Zhang, Nancy Olsen, and Song Guo Zheng. 2017. "Vitamin D and Chronic Diseases." Aging and Disease 8 (3): 346-53.

28. Aranow, Cynthia. 2011. "Vitamin D and the Immune System." Journal of Investigative Medicine: The official publication of the American Federation for Clinical Research 59 (6): 881-86.

29. Li, Xinyi, Yan Liu, Yingdong Zheng, Peiyu Wang, and Yumei Zhang. 2018. "The Effect of Vitamin D Supplementation on Blood Glucose Control in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis." Nutrients 10 (3). https://doi.org/10.3390/nu10030375.

30. Pittas, Anastassios G., Bess Dawson-Hughes, Patricia Sheehan, James H. Ware, William C. Knowler, Vanita R. Aroda, Irwin Brodsky et al. 2019. "Vitamin D Supplementation and Prevention of Type 2 Diabetes." The New England Journal of Medicine 381 (6): 520-30.

31. Kassi, Eva, Christos Adamopoulos, Efthimia K. Basdra, and Athanasios G. Papavassiliou. 2013. "Role of Vitamin D in Atherosclerosis." Circulation 128 (23): 2517-31.

32. Al Mheid, Ibhar, and Arshed A. Quyyumi. 2017. "Vitamin D and Cardiovascular Disease: Controversy Unresolved." Journal of the American College of Cardiology 70 (1): 89-100.

33. Yin, Lu, José M. Ordóñez-Mena, Tianhui Chen, Ben Schöttker, Volker Arndt and Hermann Brenner. 2013. "Circulating Serum 25-Hydroxyvitamin D Concentration and Overall Incidence and Mortality of Cancer: A Systematic Review and Meta-Analysis." Preventive Medicine 57 (6): 753-64.

34. Han, Jianmin, Xiaofei Guo, Xiao Yu, Shuang Liu, Xinyue Cui, Bo Zhang, and Hui Liang. 2019. "25-Hydroxyvitamin D and Incidence and Mortality of All-About Cancer: A Meta-Analysis of Prospective Cohort Studies." Nutrients 11 (10). https://doi.org/10.3390/nu11102295.

35. Keum, N. and E. Giovannucci. 2014. "Vitamin D Supplements and Cancer Incidence and Mortality: A Meta-Analysis." British Journal of Cancer 111 (5): 976-80.

36. Earthman, C.P., L.M. Beckman, K. Masodkar and S.D. Sibley. 2012. “The Relationship Between Obesity and Low Circulating 25-Hydroxyvitamin D Concentrations: Considerations and Implications.” International Journal of Obesity 36 (3): 387–96.

37. Anglin, Rebecca E.S., Zainab Samaan, Stephen D. Walter, and Sarah D. McDonald. 2013. "Vitamin D Deficiency and Depression in Adults: Systematic Review and Meta-Analysis." The British Journal of Psychiatry: The Journal of Mental Science 202 (February): 100-107.

38. Hughes, D.A. and R. Norton. 2009. "Vitamin D and Respiratory Health." Clinical and Experimental Immunology 158 (1): 20-25.

39.Baktash, Vadir, Tom Hosack, Nishil Patel, Shital Shah, Pirabakaran Kandiah, Koenraad Van den Abbeele, Amit K.J. Mandal and Constantinos G. Missouris. 2020. “Vitamin D Status and Outcomes for Elderly Hospitalized Patients with COVID-19.” Postgraduate Medical Journal, August. https://doi.org/10.1136/postgradmedj-2020-138712.

40. Carpagnano, G. E., V. Di Lecce, V. N. Quaranta, A. Zito, E. Buonamico, E. Capozza, A. Palumbo, G. Di Gioia, V. N. Valerio, and O. Resta. 2021. "Vitamin D deficiency as a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19." Journal of Endocrinological Investigation 44 (4): 765-71.

41. Schwalfenberg, Gerry K. 2011. “A Review of the Critical Role of Vitamin D in Immune System Function and the Clinical Effects of Vitamin D Deficiency.” Molecular Nutrition & Food Research 55 (1): 96-108.

If you are or want to be a trainer …

Learning how to coach clients, patients, friends, or family members through healthy eating and lifestyle changes – in ways that are tailored to their unique bodies, preferences, and circumstances – is both an art and a science.

If you want to learn more about both, consider the following points Precision Nutrition Level 1 certification. The next group will start shortly.

<! — Snippet to hide

If you are or want to be a trainer …

Learning how to coach clients, patients, friends, or family members through healthy eating and lifestyle changes – in ways that are tailored to their unique bodies, preferences, and circumstances – is both an art and a science.

If you want to learn more about both, consider the following points Precision Nutrition Level 1 certification.

->

The article "Should I take vitamin D?" Here's what science says. first appeared on Precision Nutrition.

Leave a Reply