Recommended dietary allowance (RDA): The average intake sufficient to meet the requirements of 97 to 98% of a group
Adequate intake (AI): The recommended average intake level based on approximations or estimates of intake by a group or groups of healthy people and that are assumed to be adequate; used when an RDA has not been determined
Tolerable upper intake level (UL): The highest average daily nutrient intake likely to pose no risk of adverse effects to almost all individuals in the general population
Detailed information on recommended intakes in the US and Canada for different age and gender groups is summarized by NASEM.3 The recommended nutrient intakes for the US and Canada were developed for healthy individuals. This underscores the unfortunate lack of research and thus the absence of formal guidelines for adjusting nutrient intake in the case of acute or ongoing illness. Given the diversity of medical conditions and variability in levels of severity, the determination of exact requirements for every illness is impractical. However, as noted in subsequent sections, a number of high‐risk conditions that are impacted by micronutrient status in older adults are known and can be addressed.
Table 16.1 Medical factors related to insufficient nutrient or energy intake and/or status.
Source: Based on Joshi and Morley1.
| Increased metabolism |
| Movement disorders: parkinsonism and Tardive dyskinesia |
| COPD |
| Severe cardiac disease |
| Anorexia |
| Drugs including digoxin, psychotropic drugs, theophylline, cimetidine, ranitidine, L‐thyroxine |
| Gallstones, chronic and recurrent infections |
| Malignancy |
| Physiological anorexia of ageing |
| Oral and swallowing problems |
| Esophageal candidiasis |
| Teeth and denture problems |
| Severe tremors and strokes |
| Malabsorption |
| Late‐onset gluten enteropathy |
| Lactose deficiency |
| Feeding problems |
| Severe tremor |
| Strokes |
| Dementia |
Medication influences on vitamin and mineral status
One of the most common concerns about nutrient needs for those with age‐related chronic illness involves the influence of medications on various components of nutrient metabolism. Use of prescription and over‐the‐counter drugs over the long term can increase the risk of subclinical and clinically relevant vitamin and mineral deficiencies, which may gradually develop over months or years.4 Examples of some of the most important diet/drug interaction are listed by drug category in Table 16.2. The number of research studies examining these interactions is small compared to the vast number of medications available.4 Information reviewed here is a brief summary from the comprehensive review of medication‐nutrient interactions associated with chronic use of frequently prescribed medications for commonly diagnosed conditions among US adults.4
Table 16.2 Medication and nutrient interactions.
Source: Adapted from Mohn et al. (2018)4.
| Drug category | Name of drug(s) | Nutrients affected | Change in nutrient status or function |
|---|---|---|---|
| Acid‐suppressing | Protein pump inhibitors | Vitamin B12, vitamin C, iron, calcium, magnesium zinc, beta‐carotene | Decreased |
| Non‐steroidal, anti‐inflammatory | Aspirin | Vitamin C, iron | Decreased |
| Anti‐hypertensives | Diuretics (loop, thiazide), diuretics (potassium‐sparing), angiotensin‐converting enzyme inhibitors, calcium‐channel blockers | Calcium, magnesium, thiamin, zinc, potassium, iron, folate | Generally decreased, but depends on the drug and the nutrient; ACE inhibitors associated with retention of potassium in the kidney, while loop and thiazide diuretics increase urinary potassium excretion |
| Hypercholesterolemics | Statins | Coenzyme Q10, vitamin D, vitamin E, beta‐carotene | Increased or decreased depending on the drug and nutrient |
| Hypoglycemics | Biguanides (metformin), thiazolidinediones | Vitamin D, calcium, vitamin B12 | Decreased |
| Corticosteroids | Glucocorticoids (oral) | Calcium, vitamin D, sodium, potassium, chromium | Increased or decreased depending on the drug and nutrient |
| Bronchodilators | Corticosteroids (inhaled) | Calcium, vitamin D | Decreased |
| Antidepressants | Selective serotonin reuptake inhibitors (SSRIs) | Folate, calcium, vitamin D | Folate may increase effectiveness of SSRI; SSRI associations with poor bone health suggest effects of SSRI on calcium and vitamin D metabolism should be investigated |
Age‐associated risk factors for the adverse influence of medications on vitamin or mineral status include marginal nutrient intakes as well as poor renal function. Polypharmacy is common in older adults, raising concerns that the use of multiple medications may exacerbate age‐related physiological changes that affect nutrient needs and drug metabolism. Although guidelines are lacking on how to manage and/or prevent drug‐induced nutrient inadequacies, it may be prudent to recommend a daily multivitamin/mineral (MVM) supplement that provides approximately 100% of the recommended amounts of vitamins and minerals (RDA or AI). Typical MVMs formulated for older adults will not provide sufficient amounts of calcium (bone health), coenzyme Q10 (which may be decreased with statin use), or fish oil (known to be beneficial for cardiovascular disease).4 These MVMs generally have low vitamin K (to decrease interactions with some anticoagulants) and very low amounts of potassium (US Food and Drug Administration [FDA] limits potassium in supplements to <100 mg; see Table 16.3).
Vitamins and minerals – functions and characteristics
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