Posts Tagged ‘Vitamin D’

Bone Breakdown: NTx Test

I just had my Annual Check-Up early yesterday morning and want to share a new test with everyone – especially for the ladies.  A good test to measure the rate of bone breakdown is through something called the N-telopeptide test (or NTx test).  This is a simple and non-invasive test: urinate into a cup; the doctor finds out your results.  A normal result is anywhere between 0.45 – 4.5 uIU/mL.  Why you want to do this: women have an increased risk of developing osteopenia (low bone density), which is a precursor to osteoporosis later in life.  During your 20s and 30s, you can rectify low bone density much faster than later on in life.  You can do so through increasing vitamin D (supplements, sunlight and food sources) and by weight training (adding a stress to the bone produces bone cells).  Treatment through supplementation and weight training is warranted once you know where you stand, so ask for the test! To learn more about other tests you should take at the doctor’s office, visit the the Health Checklist Channel.



Vegetarian Sources: Vitamin D & B12

Vegetarians are known to have low levels of both vitamins B12 and D (since the best sources of these vitamins are found in the flesh of fatty fish, seafood and meat products).  Luckily, many foods are now “fortified” with vitamins B12 and D.  When a food is fortified, it means the company has added vitamins and minerals to enrich the product’s nutritional value.  How to detect if a product is fortified?  #1 Look for the Nutrition Facts label. #2 At the bottom of the label, a product is required to list the amounts of vitamins A and C, and the minerals calcium and iron.  #3 Many times there are additional vitamin or mineral listings, in order for a company to market the product as, “an excellent source of B12!” or, “enriched with vitamin D.”  Some examples are: Kashi’s Heart to Heart cereal (100% B12); Soy Milk (50% B12; 30% vitamin D).  Other B12/D vegetarian sources include: nutritional yeast (which are flakes to add to yogurt, cereal or oatmeal), orange juice, dairy products, eggs and veggie burgers.

Maximize B12 with Food Sources:

  • Breakfast ideas:
    • 1 cup heart to heart cereal with soy milk
    • 1 cup yogurt (half DV B12) with nutritional yeast
    • Lunch ideas:
      • Tofu (good source) with veggies and brown rice
      • Snack: 1 cup soy milk with a piece of fruit
      • Dinner:
        • Veggie burgers (fortified with B12!)
        • Whole wheat bread (fortified!)

Maximize Vitamin D with food sources:

  • Milk and Soymilk
  • Yogurt
  • Eggs
  • Swiss Cheese (also has B12)

Should I Take Cod Liver Oil?

I recommend cod liver oil only if your goal is to use it as a vitamin D supplement, but it is very high in vitamin A.  Although cod liver oil is moderate in omega-3 fatty acids, I do not recommend it as a fish oil supplement since there are better options higher in omega-3s on the market.  I will review some of my recommendations below.

Why Should I Care About High Doses of Vitamin A?

One word: Hypervitaminosis A.  We never want to take in over 10,000 IUs of vitamin A per day. High vitamin A can result in a number of different complications.  Women can increase the risk of bearing a child with birth defects, and both men and women can increase the risk of hair loss, liver problems, skin discoloration, and bone mineral density loss.

1 teaspoon of cod liver provides 4,501 IU of vitamin A –1 teaspoon is a small amount!  Many people might take upwards of 1 tablespoon, which provides 13,502 IUs of vitamin A.  This is too much.

Isn’t Cod Liver Oil Full of Omega-3s?

1 teaspoon only provides a total of 888 mg omega-3s. We want to get at least 1000-2000mg omega-3s per day, meaning if we consume the recommended amount for omega-3s via cod liver oil we exceed the daily recommendation for vitamin A (which is toxic, as explained above).

Although cod liver oil is considered an omega-3 source, it is not nearly as high in omega-3s as other fish oils per 100 grams of fish:

Atlantic Salmon: 2.15 omega-3s
Atlantic Herring : 2.01 omega-3s
Sardines : 2.0 omega-3s
Mackerel : 1.85 omega-3s
Cod Liver : 0.28 omega-3s

Is There Ever an Instance When You Would Recommend Cod Liver Oil?

I recommend cod liver oil when compliance is an issue (forgetting to take), i.e., if you are not a fan of taking supplements but need to increase both omega-3s and vitamin D in the diet, then cod liver oil is and excellent choice. In that case, 1 teaspoon is sufficient.

What Brands Do You Recommend as a source of Cod Liver Oil? Vitamin D? Omega-3?

All of the following supplements are NSF-certified.

Cod Liver Oil and Vitamin D: try the Nordic Naturals line

Vitamin D and Calcium only: try Premcal (yes it says for “PMS” relief, which high Vitamin D levels have shown to help in some cases, but it is a good supplement for anyone looking to amp up calcium and D)

Omega-3s: omega-3 sources come from both fish and algae. For vegetarians, they should make sure they are not taking supplements that are fish-based. Below are my recommendations for both groups:

For non-vegetarians, I recommend the Nordic Naturals line.

For vegetarians, I recommend algae oil (known as Algal Oil).  Martek is an NSF-certified brand.  Natrol DHA Omega-3 is USP certified; I would go with the first since there is more DHA, but it is also a little more pricey.

Exercise’s Role in Building Bone

Parents always say, “drink your milk for healthy bones.”  They are correct due to the high amount of calcium and vitamin D supplied in milk–necessary for the lay down of new bone cells.  But exercise seals the deal.  Why?

Exercise’s Role in Building Bone

When the bone receives a load upon it via some form of physical work, such as weight training or any other exercise that puts a force on the skeleton, the “osteoblasts” (cells that help bone form) will be activated.  The osteoblasts bring calcium into the bone to help strengthen it up.

The Research: Why Start Young

A recent study published in Medicine & Science in Sports Exercise has recently suggested that the opportunity to build bone may happen as early as five years old!  The study found that children with the highest levels of moderate and vigorous physical activity at age five accumulated between 4-14% more bone mineral content at ages eight and 11 than those with the lowest levels of activity.  This suggests that exercise can help increase the propensity toward building bone–especially when starting at a young age.

Another study published in the Journal of Applied Physiology found that the lower a child’s calcium intake, the more important for daily exercise.  They researched girls and boys ages 8-11 who engaged in 25-40 minutes of physical activity per day AND consumed between 700-800 mg calcium per day.  They found that the group who consumed calcium with the daily physical activity built up and retained the greatest bone mass.

The Recommendations for Exercise for Children and Adults

The American College of Sports Medicine (ACSM) and American Heart Association (AHA) recommend that children partake in 60 minutes of some physical activity every day.  For adults, the ACSM and AHA recommends moderately intense cardio 30 minutes per day, five days per week.  If you cannot do that, they recommend vigorous intense cardio 20 minutes per days plus three days a week devoted toward strength training exercises (8-12 repetitions of each exercises two times per week). (1)

If you want to have the strongest bones, strength training should be added at least twice per week to make sure the skeleton receives the greatest exercising load. Here is a WHY TO exercise, in case you have forgotten!

The Recommendations for Calcium & Vitamin D

Peak skeletal growth happens between teenage years and the mid 20s.  Teenagers can accumulate up to 25% of adult bone during that time period. (2) Sadly, sodas (both regular and diet) tend to take the place of nutrient-rich beverages like milk.  As a result, calcium intakes have fallen short of the recommendations for children aged 4-8 to consume 1,000 mg per day.  See the Institute of Medicine (IOM) recommends below, which details the following most recently updated intakes of calcium and D for children and adults:


(1) ACSM and AHA Exercise Guidelines

(2) Bailey DA, Martin AD, McKay HA, Whiting S, Mirwald R. Calcium accretion in girls and boys during puberty: a longitudinal analysis. J Bone Miner Res. 2000;15(11):2245-2250.