Question

Barbara has come to you, her Dietitian, for a nutrition evaluation. Barbara is an 85 year old female recently diagnosed with osteoporosis. She weighs 115 pounds and is 64 inches tall. Unfortunately, last week she had a fall that broke her hip. Barbara suffers from chronically poor appetite and therefore eats a limited diet. Barbara tells you that her usual intake is fruit juice and toast with butter for breakfast, cottage cheese and fruit or tuna and toast for lunch, and a frozen meal for dinner consisting usually of chicken, rice, and vegetables. Before bed she often drinks a glass of warm milk. Barbara's serum vitamin D level on her most recent bloodwork is below normal. Barbara lives in Southern California, but she spends most of her time indoors. During this hospital visit for her broken hip, Barbara was prescribed a blood thinning medication by the doctor.

Please answer the following questions related to Barbara's story:

1. Which factors might put elderly people at risk of vitamin D deficiency? (2 points)

2. What food(s) in Barbara's diet are the best sources of vitamin D? (2 points)

3. Since Barbara's serum vitamin D is low and her usual diet does not contain much vitamin D, you consider recommending a vitamin D supplement for Barbara. What factors will you tell Barbara to consider when selecting a supplement? (List three factors.) (4 points)

5. Since the doctor prescribed a blood thinner to Barbara, you tell her that vitamin K rich foods might interfere with her medication. What will you tell her about vitamin K rich foods? (that is, should she eat more, less, or consistent amounts of vitamin K?) Which foods are rich in vitamin K? (2 points)

Answer 1

Question number: 1

Elderly people are at more risk of vitamin D deficiency because

1. With age there is thinning of the skin which reduces vitamin D synthesis in the skin. Obese people also have less vitamin D synthesis in the skin.

2. Complexion of skin- fair or light skin produces more vitamin D than darker tones of skin.

3. In skin 7 dehydrocholesterol (precursor) is converted to provitamin D3 which is later hydroxylated in the liver(25-hydrocholecalciferol). This hydroxylated form is further metabolized and converted to a biologically active form in the kidney(1-25 di hydrocholecalciferol). Both of these processes also decline with age.

4. Elderly stay mostly indoors or have limited sun exposure. Keeping the body covered while in sun and use of sunscreens also decreases vitamin D synthesis by the skin.

5. Decreased dietary intake of food rich in vitamin D (more common in strict vegetarians, those with milk allergy, lactose intolerance) as well as an overall reduction in dietary intake due to loss of appetite secondary to inactivity or effects of drugs taken for chronic conditions.

Question number: 2

Foods in Barbara’s diet which are the best sources of vitamin D are Tuna and cheese.

Some pre-packaged juice is also fortified with vitamin D, but there is no information on this regard whether Barbara’s juice is homemade or fortified one.

The same is for milk, it may or may not be fortified depending on the source. Without fortification milk is low in vitamin D.

Question number : 3

Factors Barbara should keep in mind while selecting vitamin D supplement are:

1. The form of vitamin d that is whether D2 or D3. Both are good for preventing or treating vitamin D deficiency but vitamin D3 has longer half-life therefore less frequent dosing is required.

2. Supplements are regulated by US Pharmacopeia not by FDA. So look for the USP mark of approval on the product’s label.

3. Taking too much vitamin D dose can also be harmful. So take them after measurement of vitamin D and also get it checked periodically thereafter. Higher levels of vitamin D can be toxic sometimes, it can lead to an increased level of calcium in the body. Too much calcium may result in deposition and hardening of blood vessels and also increases the risk of kidney stones.

4. Regarding form one can go for power, liquid, or soft gel capsules.

Question number : 5

Some foods can interfere with the effectiveness of blood thinners. Warfarin is a commonly used blood thinner. Eating an increased amount of foods rich in vitamin K can lower prothrombin time reducing the effectiveness of blood thinners and potentially increasing the risk of blood clots.

Therefore people who take blood thinner should aim to eat a relatively similar amount of vitamin K each week.

The high amount of vitamin K is found in green and leafy vegetables such as broccoli, lettuce, amaranth, collard, kale, spinach, and kiwi fruit.

It is not necessary to avoid or increase the intake of these foods. But it is important to try to keep the amount of vitamin K in food consistent.

Foods low in vitamin K are avocado, celery, carrot, banana, corn, cucumber, tomato, cauliflower, pumpkin, potato, radish, turnip. She need not opt for low vitamin K food. Consistency is the key.

Alcohol intake can affect how the body metabolizes certain blood thinners. So one should avoid drinking alcohol daily. Alcohol should be limited to no more than 1 to 2 servings of alcohol occasionally. The antiplatelet effect of alcohol increases the risk of major bleeding, even if the INR remains within the target range.

The most important point to remember is one should eat what he/she normally eats and not to make any major changes in the diet without contacting your healthcare provider.